Is this '78 GMC worth $4500?

[J S Machine]

Wife and I were driving through town yesterday and here is this '78 model GMC truck with a lift and tires. I looked at my wife and said "Man I'd love to have that thing"..so she says "why don't you buy it"..

http://i226.photobucket.com/albums/dd198/JSMachine/2012-05-13_14-54-01_302.jpg

I don't need permission from her, I'm just kind of a tightwad and have held off on alot of things I really want because I just don't want to spend the money. I have a '95 model Z71 ex-cab right now, but I've always wanted one of these older body style trucks. People know what they have too. I once offered a guy who had a similar older model a straight up trade for my Z and he laughed in my face. The seller of this '78 wants $4500, and it seems fair, if not good.. I know a little about these old trucks, but not enough to be 100% confident in buying one.

I can pay cash, and later on if I decide I don't want it, I would think I can get my money back out of it.

What I know about it after talking to him

350 (not sure if original)
Auto trans (not sure if it is a 350 or 400 turbo)
No rust, all new paint, underside and body. It really looks good up close
Interior looks like 1978, other than a seat cover
All new seals in everything underneath, incuding dropping transfer case and rebuilding it.
New brakes
I see an electric fan up front.
Nice wood in the bed seperated by metal strips
New wheels and tires, he said they might have 500 miles on them

He said the reason it doesn't have a front drive shaft in is because of the vibration it causes when it's in. I am unsure if this is full time 4x4 or not. If you look at the pics you can see what appears to be locking hubs. A friend of mine tells me the only real reason the front drive shaft would vibrate is because of the driveline angle being off. I think I heard the guy say that he put the rancho lift on the truck. My buddy says if the driveline angle is off, it will do this, but the rancho lift should have come with wedges to offset it and correct it. Seller claims he took it out to avoid wearing out the seals up front. I'm assuming it is full time 4x4, because wouldn't you just knock it out of 4x4 and drive like normal?

I need more info on this please.

The gas is not an issue. I drive my Z, once a week, if that. This will be a drive on occasion kind of truck..mainly a backup vehicle. I don't really have room for my current Z and this '78 if I were to buy it, but I would probably have to get rid of my Z. I dont know which truck is worth more in the event that I buy this '78. You can't find these old trucks very easily, and Z's like mine are a dime a dozen.

This is a pic of my Z

http://i226.photobucket.com/albums/dd198/JSMachine/truck/truck5.jpg

The maintenance is not really an issue either because I like tinkering with stuff. Like I said, I like the old truck. I'm just not sure if it would be a good buy. I would offer $4k cash and see if he'd take it. Is it worth it?

[97vortec383]

I don't know too much about pricing of these truck but a few things make me think it isn't too bad:
1. Paint/body has been taken care of and you don't have 34 years of rust to worry about
2. Suspension and tires/wheels are brand new, what's to argue there.

From what you said I think the price would really just depend on the condition of the engine/tranny and how it drives. If they check out good then I don't think $4K is bad for a good running, lifted, bad ass looking truck that you've been wanting for a while.

[rich weyand]

I'll throw in a couple of things. Others here know much more, but I'll get the ball started.

In '78 most 4x4s came with long beds. This was before people bought 4x4 pickups as pseudo sports cars, so most 4x4s were for construction guys who wanted the long beds. So give a peek underneath and see if the frame has been shortened. This will be indicated by a weld seam between the rear of the cab and the front spring mounts for the rear axle. A zig-zag seam is maybe OK, a straight seam is not. Check for quality of the seam weld if it's there. Look close, they may have ground it down, but you would probably still detect it.

Check the oil color. If it's blackish, it's idling rich, which is a fuel leak in the carburetor. The plugs in the machining holes of the Qjets can develop fuel leaks, which are a bigger problem at high vacuum and low air flow, which is to say when idling. There's ways to fix these too, so not fatal, but easy to check for.

If it has locking hubs, then he probably modified the NP203 transfer case to make the full-time 4WD a part-time setup. That's OK, but when 4WD is disengaged and the hubs are unlocked, the front driveshaft does not spin, so I don't see where a vibration would be coming from. Removal of the driveshaft is probably a sign of a problem that you're not getting the straight story on. Anything can be fixed, and if the rest of the truck is in good shape that's a sweet deal, but have your eyes open going in.

I paid twice as much for mine. But it was in good shape, fleetside shortbed which is what I wanted, in black which is my color, so it was perfect for me. So the money doesn't sound bad to me. Then again, I probably overpaid but it was exactly what I wanted and when I wanted and a reasonably close drive to go get it, so I just said heck with it and got it.

Rich

[J S Machine]

In '78 most 4x4s came with long beds. This was before people bought 4x4 pickups as pseudo sports cars, so most 4x4s were for construction guys who wanted the long beds. So give a peek underneath and see if the frame has been shortened. This will be indicated by a weld seam between the rear of the cab and the front spring mounts for the rear axle. A zig-zag seam is maybe OK, a straight seam is not. Check for quality of the seam weld if it's there. Look close, they may have ground it down, but you would probably still detect it.

Great advice, I will ask and also look.


Check the oil color. If it's blackish, it's idling rich, which is a fuel leak in the carburetor. The plugs in the machining holes of the Qjets can develop fuel leaks, which are a bigger problem at high vacuum and low air flow, which is to say when idling. There's ways to fix these too, so not fatal, but easy to check for.

I'll do it. The truck has an edelbrock carb, so I assume the motor probably isn't original. He says it smokes a little blue smoke on startup, but only for about 10 seconds. I have not heard it run yet, or seen the engine form the top. this could mean leaky valve seals or it could be running rich. He says the truck has been sitting for a while, so I have to factor that in too. I can rebuild the carb with my eyes closed though, so not an issue if that is the problem.


If it has locking hubs, then he probably modified the NP203 transfer case to make the full-time 4WD a part-time setup. That's OK, but when 4WD is disengaged and the hubs are unlocked, the front driveshaft does not spin, so I don't see where a vibration would be coming from. Removal of the driveshaft is probably a sign of a problem that you're not getting the straight story on. Anything can be fixed, and if the rest of the truck is in good shape that's a sweet deal, but have your eyes open going in.

From the way I had it explained to me by someone else, the full time four wheel drive means that everything spins, all the way down to the hubs. when the hubs are locked in, the front wheels turn. I was thinking the driveshaft would not spin either, but I don't have expeieince with anything other than my truck which is a '95 Z and IFS front axle.

[rich weyand]

I'll do it. The truck has an edelbrock carb, so I assume the motor probably isn't original. He says it smokes a little blue smoke on startup, but only for about 10 seconds. I have not heard it run yet, or seen the engine form the top. this could mean leaky valve seals or it could be running rich. He says the truck has been sitting for a while, so I have to factor that in too. I can rebuild the carb with my eyes closed though, so not an issue if that is the problem.

Mine had an Edelbrock, but with the original engine. This is a "quick fix" instead of rebuilding a Qjet. Probably also took off the induction system too, and replaced it with the "two chrome pie plates" air cleaner setup. See my adjacent thread on the induction system changes I just did to my 78 for full discussion.


From the way I had it explained to me by someone else, the full time four wheel drive means that everything spins, all the way down to the hubs. when the hubs are locked in, the front wheels turn. I was thinking the driveshaft would not spin either, but I don't have expeieince with anything other than my truck which is a '95 Z and IFS front axle.

The NP203 was the full-time 4WD transfer case in '78. It had a differential in the transfer case. These are often disabled, changing the "differential 4WD" and "locked 4WD" selector settings to "2WD" and "locked 4WD". The original did not come with manual locking hubs -- these are generally added when the transfer case is modded. When the hubs are free and 2WD is selected on the transfer case, the driveshaft and front differential are not driven from either side. So something is going on there with the driveshaft being removed. I'm not sure you have the full story from him. For more NP203 discussion, see my post from last year. Search "weyand NP203".

Rich

[Quyonmob]

Alot of guys incorrectly slapped manual hubs on NP203 trucks without converting the t-case to part time.

I would bet this is the case here, as;

1 - The t-case needed rebuilding, likely from not being properly converted to part-time, but being operated with manual hubs (usualyl teh truck wont move this way, due to the center diff).
2- The front DS is removed as it was causing a vibration in 2wd (would be impossible if the NP203 was converted to part time and the hubs were unlocked).

Double CV shaft will cure steep operating angles, may need a little more space aroun the trans X-member to fit it.

[UnderCover W/T]

I say buy it. I have regretted buying a black 84 4x4 stepside with a rebuilt 350 for two years. (Whatever my 89 silverado rules hard...)
4k is a good base price if it does end up needing a little more. In PA, these trucks are hard to find in decent condition and when you do find them they are rusted to **** or completely rebuilt and costing 8k+

[J S Machine]

Just had another conversation with the guy.

The seller and his son built this truck but are now selling it. He said the reason he got his son another truck is because he neeeded something more economical. He could not afford the gas in this one as a daily driver.

Said the bed was replaced, floor boards patched, hood replaced, and a door. Said he eliminated all rust he could find. The truck was painted by a body shop I know of, and said he paid $1200 for the BC/CC paint job.

warn locking hubs up front, said it is not full time 4x4. Not sure if this makes sence or not. I'm still gonna have to see the transfer case and look for the tab.

Truck does have AC and heat. He put a new heater core in too. AC will not hold refrigerant for long so it has a leak..

I'm going this afternoon to look at it and drive it, so I need to know anything I can on what to look for. I am going to check out the whole drivetrain issue and see what its about. I need to fully understand the whole thing and the difference between the different T cases.

[rich weyand]

If it's not full-time 4WD, then either it has an NP203 that has been modded, or it has been fitted with something like an NP205. You can find identification pictures for these two on this page: http://67-72chevytrucks.com/vboard/showthread.php?p=3696641

If it is an NP203 that was modded, it may have needed to be rebuilt because a lot of people don't know that you must run an NP203 in 4WD (even if the hubs are unlocked) once in a while (every hundred miles or so) to lubricate the output shaft bearings. Being designed for full-time 4WD, there is no oil pump in the unit -- the chain handles that. But the chain only turns when the transfer case selector is in one of the 4WD Locked positions. I just put mine in Locked whenever I start out on a trip, then slip it out of Locked after a mile or so, which you can do on the roll.

See this thread:
http://www.fullsizechevy.com/forum/general-discussion/classics/466041-locking-hubs.html

Rich

[Quyonmob]

^This is good stuff. I knew there was some trick to keepign an NP203 oiled after a part-time conversion.

[J S Machine]

Went and drove the truck yesterday. The list of stuff that is new on this thing is just off the charts. Add a new fuel tank (and possibly dual tanks). New filler hose. new heater core and some hoses. All vital guages are aftermarket and work. The speedo is the only thing that doesn't work, but on a rig like this it isn't uncommon.

Inside is less than ideal, but you can tell the attention was focused on the outside. The body is absolutely straight. I could not find any rust. He did a very good job whith the rust. The frame has not been sectioned and shortened, like you guys told me to look for.

It has a NP203 transfer case and Warn locking hubs. The front axle yoke is horizontal, confirming the "no shims" in it like he said. Now that we know it has a 203, we know this was originally a full time 4x4, Correct? Is there any way to tell whether it has been converted to part time? I need to know this because I want to check before I buy.

The truck has some get up and go, but the carb is not right. It has an edelbrock carb, and it is way out of whack. The truck sat there and ran for about 15 minutes in park before I drove it, and it did not run hot or anything. No cam; the motor is pretty close to stock. I don't think it is original, but the only way to tell is to check the block ID number against the VIN. I will do this. It does have an HEI cap. but the block has V belts (indicating a little older motor). I didn't think these came with HEI in '78, but I could be wrong.

The truck drove worse than I expected. This is my first experience with a lifted truck, and man this thing rode rough. it drives alot like a tractor. If it wasn't for the springs in the seat I think I would have been beat to death lol. according to several of my friends, this is just the way they ride when lifted like this. The steering felt good. I forgot to check if it had power or not, but I assume it does because it didn't take much efft to turn. The brakes are really stiff. I know the truck is big and the tires are big, but the brakes were very hard to apply. In my past experience with another car, the master cylinder was bad. After putting in a new master cylinder and bleeding the brakes, it helped alot. The booster itself may be bad.

I took it out for a drive and it promply flooded out and quit after climbing a very steep hill. I knew this might happen going in and I had done that to see how the carb would act. Seller didn't lie about this, he knew the carb was not right. I did eventually get it cranked, but only after letting it sit for a while and applying choke.

I went back and told the guy $4k. I told him I was not doing anything until he put another carb on (preferablly a double pumper holley with mechanical secondaries) and got it right. I want to be able to know the motor is fine and it is hard to diagnose anything about it at the moment with the current carb. I'm not sure what carb would be best for the truck, but I assume that one I mentioned would be easy to play with.

He said he would take $4k. I told him to give me a call when he gets a new carb on, and that I would come take another look. I figure this is a good stance to take. He will probably try to tell me he's not going to take $4k because of putting money into a carb, but I'm going to stand firm on it. In a day or two if I haven't heard from him I'm going to call back and ask about the carb. If he hasn't figured that out yet I'm going to tell him $3800 as is, and I'll deal with the carb.

So, will sit and wait.

I thought I had gotten a picture of the front axle, but my ohone didn't save it for some reason. I don't know if it is a Dana, but one of my friends says it wasn't uncommon to have a Dana under there from the factory. I'm not sure how to tell.

Here are some pics.

http://i226.photobucket.com/albums/dd198/JSMachine/2012-05-14_16-28-26_94.jpg

http://i226.photobucket.com/albums/dd198/JSMachine/2012-05-14_16-28-39_961.jpg

http://i226.photobucket.com/albums/dd198/JSMachine/2012-05-14_16-28-48_602.jpg

http://i226.photobucket.com/albums/dd198/JSMachine/2012-05-14_16-31-04_210.jpg

[Quyonmob]

It has power steering, your arms would be screaming for mercy with no power steering and tires that big in parking lot.

Vaccum brake boosters back then were pretty weak, as were the OE master cylinders, makes for alot of "leg leverage" required to get big tires stopped.

On the carb, rochester Q-jet would be my suggestion, get it tuned once by a pro and "set it and forget it", handles hills better than any "performance" carb as well. More than enough carb for a 350 that is near stock.

D44 would be the OE front axle in 78. Front axle can't be shimmed very far to correct pinion angle, as it destroys caster specs. Double CV shaft will handle that angle.

Rough riding leaf lifts are pretty common, longer leaves quite often help, but now you are into more work and money.

[J S Machine]

It has power steering, your arms would be screaming for mercy with no power steering and tires that big in parking lot.

Vaccum brake boosters back then were pretty weak, as were the OE master cylinders, makes for alot of "leg leverage" required to get big tires stopped.

On the carb, rochester Q-jet would be my suggestion, get it tuned once by a pro and "set it and forget it", handles hills better than any "performance" carb as well. More than enough carb for a 350 that is near stock.

D44 would be the OE front axle in 78. Front axle can't be shimmed very far to correct pinion angle, as it destroys caster specs. Double CV shaft will handle that angle.

Rough riding leaf lifts are pretty common, longer leaves quite often help, but now you are into more work and money.


Can you tell if that is a Dana 44 by looking at the one pick I have of it? Would it be anything else by chance? I had heard this would be what is preferred.

[rich weyand]

It has a NP203 transfer case and Warn locking hubs. The front axle yoke is horizontal, confirming the "no shims" in it like he said. Now that we know it has a 203, we know this was originally a full time 4x4, Correct? Is there any way to tell whether it has been converted to part time? I need to know this because I want to check before I buy.

If the NP203 has not been modded, then without a front driveshaft the truck will not move in Unlock. The transfer case differential will spin the front shaft output and nothing will go to the rear. So if it drives in Unlock, it's modded.


The truck has some get up and go, but the carb is not right. It has an edelbrock carb, and it is way out of whack. The truck sat there and ran for about 15 minutes in park before I drove it, and it did not run hot or anything. No cam; the motor is pretty close to stock. I don't think it is original, but the only way to tell is to check the block ID number against the VIN. I will do this. It does have an HEI cap. but the block has V belts (indicating a little older motor). I didn't think these came with HEI in '78, but I could be wrong.

The Edelbrock is easy to set up. Usually they are set up richer than hell in the stock setting so people who can't tune a carb can drop them on and go without running way lean and burning up an engine. Drop to some 092 jets on the primaries and probably some 065x057 rods and you would be good to go.

[TheBigMortboski]

A few things:

- HEI and V-belts are both correct for this year. 1974 was the last year for points (at least in cars, I'd assume trucks too)
- A Holley double pumper would be too much carb for a stock-ish engine. I had one on my old Nova with a somewhat modded 350, and I yanked it off for a 600 single feed vacuum secondaries, and it ran much smoother, idled better, and got better mileage (9 to 11 was a pretty big improvement, all things considered).
- If you plan to take it offroad, a Quadratoilet would probably be your best bet. This is all pretty old 2nd hand info, but from what I heard they are the best for staying running at extreme angles. Second would be Holley, last would be Carter AFB/Edelbrock. And as far as ease of tuning, I'm a Holley man myself. Just take the metering block off, change your jets, set your float level with the sight glass, and you're golden.

[rich weyand]

Couple things on the pictures:

- Those gauges aren't stock in the four-gauge group on the left.

- A/C was probably added, or the instrument bezel was swapped out, because you have the A/C ducts on the passenger side, but not the two on the drivers side in the instrument bezel, which should be 1) to the left of the headlights and 2) above the heater controls.

- The vacuum advance line is hooked up wrong, though it may be the stock setup. It will idle much better and have better off-idle performance if the vacuum line to the distributor is moved to the right-hand side port on the Edelbrock, so it's pulling vacuum from below the throttle plate (intake vacuum) instead of above the throttle plate (port vacuum). Put a T in that line, hook it up there, then cap off the port vacuum line.

Rich

[J S Machine]

Couple things on the pictures:

- Those gauges aren't stock in the four-gauge group on the left.

- A/C was probably added, or the instrument bezel was swapped out, because you have the A/C ducts on the passenger side, but not the two on the drivers side in the instrument bezel, which should be 1) to the left of the headlights and 2) above the heater controls.

- The vacuum advance line is hooked up wrong, though it may be the stock setup. It will idle much better and have better off-idle performance if the vacuum line to the distributor is moved to the right-hand side port on the Edelbrock, so it's pulling vacuum from below the throttle plate (intake vacuum) instead of above the throttle plate (port vacuum). Put a T in that line, hook it up there, then cap off the port vacuum line.

Rich

You are correct, the guages are not stock. I'm kind of glad though, because I'm sure these aftermarket ones work a little better.

The AC/Heat deal being all weird isn't really an issue, I can work on that. I never expected a truck like this to have AC, so my feelings are not hurt if it does't work. I will look into it, but not a major concern at all. Heat would be nice, but not a huge issue either.

I'm wondering if I should call him back and get him to meet me up there again, and let me look at the vaccum line. I'd like to be able to take some with me, including a T, that way I can plumb it the way you suggest and see if it improves it. I'm not sure what size hose I might need though. I don't know that it will help the flooding issue, but maybe so. If I can talk him into this, and it runs ok but not great, I can offer $3800 and tell him I will deal with the carb. This way he doesn't have to agrivate with it.

In addition to that, I'd like to be able to listen to the bottom end somehow, and check for a spun bearing. I've never done this and I don't really know what to listen for. I know it would require some sort of stethescope. It will be difficult anyway, because the truck has glass packs. I have a compression guage, but I think pulling every single plug right there in the parking lot in front of him would be a little much. I just want a surefire way to check on the motor, that way I have some confidence in it.

[Quyonmob]

Can you tell if that is a Dana 44 by looking at the one pick I have of it? Would it be anything else by chance? I had heard this would be what is preferred.


I can't, someone else may be able to... BUT the GM 10 bolt front and Dana 44 front are nearly identical, so it's no big deal either way.

[Emersonsdad]

Can't you tell the Dana by some numbers on the axles? Then next time he checks out the truck he'll be able to tell.


Sent from my iPhone 5 using Tapatalk

[J S Machine]

Decided not to buy the truck. Seller has now taken the edelbrock carb off, and claims to be replacing it with another one (not sure what brand) that his son's friend has. -Supposed to get the truck running right.

Then he admits to being upset and aggravated when he agreed to the $4k price, and claims he has talked it over with his wife and she tell him he cannot take less than $4500 for the truck.

I offered $4k as is, and he kept on about the $4500 number and wants to wait until he gets it running right to show it to me again.

He has giveen me too long to think about it. At the very least, this other carb he is getting will still not be correct, and I'll have to buy a new carb. Something he refuses to do apparently. I hate to pass up the truck but I think my money is better spent elsewhere.

[SolMan98]

Leave hime your name/number and tell him if he changes his mind to call you. But mention that you are still looking and never know when you will find the one you will buy.

[vic_V8]

I bought this truck for $3800 in a state where rust is a big issue:

http://i161.photobucket.com/albums/t227/vic_V8/84trk6.jpg
http://i161.photobucket.com/albums/t227/vic_V8/truck35s.jpg
http://i161.photobucket.com/albums/t227/vic_V8/DSC00602.jpg
$1500 later
http://i161.photobucket.com/albums/t227/vic_V8/DSC00599.jpg

[HawgEnvy]

For future reference,a 10 bolt is more round and has two distinct ears on the bottom of the diff. Check the rear axel in your Z and you'll see the same thing. Dana axels are stamped between the ribs on the pinion side of the diff. D44,D60,etc.

There are tags on the t-case to identify and the 203 shifter reads "Hi-low(loc)". 205 are a part time gear driven case as opposed to the 203 full time chain driven. The 205 is by far the most preferred of the two.

As stated,drive line vibes can be cured w. a CV shaft for the angle. However,if you have a heavy foot,the 12 bolt rear and D44 will likely not last long combined with that much rubber.

If you want a truck that size, expect a rough ride with the arch of those springs. A better solution,IMO,is to find a non-lifted 3/** and do a mild lift. I stuffed 36/14.5/16.5 Tsl swappers on my 3/** w stock height and some trimming. Slight rubbing on inner front fender wells at full steer. No problems on the rear

[brandoon12]

looks great man, perfect tire size and lift

[UnderCover W/T]

I bought this truck for $3800 in a state where rust is a big issue:

http://i161.photobucket.com/albums/t227/vic_V8/84trk6.jpg
http://i161.photobucket.com/albums/t227/vic_V8/truck35s.jpg
http://i161.photobucket.com/albums/t227/vic_V8/DSC00602.jpg
$1500 later
http://i161.photobucket.com/albums/t227/vic_V8/DSC00599.jpg
Looks beautyful

[95BlackTahoe]

Looks beautyful


Agreed!

[bigolblackie]

Hope your lucky enough to find the truck of your dreams,before you get too old to have fun with it. If your trying to buy something,anything!,and you are able to get the price down,buy it! right then,or else the seller will go back to wanting more money,what he thinks its worth(which is what matters) I thought that was a very nice truck,worth the $4000 asking price. Good luck finding something else.

[dcZ71]

I wouldn't let that truck go over 500 bucks, its too nice. You can't find these old trucks in good shape anymore.

[GreaseDog]

I wouldn't let that truck go over 500 bucks, its too nice. You can't find these old trucks in good shape anymore.

They're not that hard to fill with bondo either... Just sayin. I will never buy a vehicle with fresh paint, too easy to hide fresh body work under fresh paint, especi&lly white. There is a reason most fleet trucks are white... It hides body imperfections very well.