86 GMC K10 Ex cab

[choptop]

Just got another ex cab added to the fleet. this one has the 6.2 in it. I have to replace the headgaskets, and have been reading some as far as modifications. Question I have is how much benefit is there to getting rid of the egr type intake manifold, and what benefits from exhaust upgrades can i look for. As a gas guy, I have Flowmasters on everything, not sure about a diesel tho. Turbo upgrade will be in the future, but far future. I just wanna drive it. Thank you for any ideas or suggestions.
http://i257.photobucket.com/albums/hh203/choptop76/smokey/SANY0087.jpg
http://i257.photobucket.com/albums/hh203/choptop76/smokey/SANY0092.jpg
http://i257.photobucket.com/albums/hh203/choptop76/smokey/SANY0104.jpg

[andy howell]

i have run a bunch of 6.2s & still have two. i have always changed the intake for a j model. i use stainless steel shim stock to block the exhaust passages on the heads. ain't never noticed any power increase, but all the other work i did at the same time really helped! also keeps the mess down in the ole intake.
andy

[choptop]

Thanks for the info. Any exhaust size recommendations?

[crossy's son]

I'd go with a nice true 3" Single or 2.5" True duals.

Actually i believe they came stock with true duals that are like 2.25 I'd say stick with them but put some good mufflers on them , if you ever plan to put a turbo on it i wouldnt spend much money on the exhaust since the whole system will have to be changed when you add a turbo

personally i wouldn't go with flowmaster. I'd go with glasspacks :)

i think the pingy sound of the engine would go right through the flowmasters and make it sound like a$$...

[ryan_thompson87]

Where the hell do you find all these things? :lol: Still got the lifted red one?

[M.$terner]

looks pretty clean but im not a fan of running boards. dont see many of these in the ex cab though. bet thats prety rare

[ryan_thompson87]

They were conversions done in texas. I think he has 4, which is 4 more than I had ever seen before.

[choptop]

Hello Ryan. Yeah, I still got the red one. Took it out for a spin just the other day. Ive got 5 of them now and I guess its just a blessing to be able to find them. Ivre wanted a diesel for a long time, just didnt think Id find it in an ex cab. Its the only one that I know of with the diesel. The list is 1-85 Chevy K10, 1-85 K20, 1-86 GMC K10,I 86 GMC C10, and 1 86 Chevy K30 extended crewcab.

[Coburn]

I think that's the coolest thing ever.

What I'd give to have one :D

[mtjasper]

The J code intake makes it breath better, but it really helps clean up your engine too. If ya look in your intake, you'll see all the soot, thats from the EGR, i mean, who really wants that? You can either swap intakes, or make a small blocker plate. I have glasspacks on my truck and they sound great, but a naturally aspirated 6.2 needs back pressure to run good, or say bye bye to your bottom end torque. I'd suggest getting a pyro gauge before you go adding a turbo, and turn up the pump a little, it really wakes these old girls up, then your free to turbo, but try not to go over 10 psi, then you run the risk of over boosting or running the stock GM turbos way out of their efficiency range.
Heres a video a buddy of mine made on how to turn the 6.2 IP up

http://www.youtube.com/watch?v=Hnoct-21vNY

[countryson]

everything mt said is true. egr does hurt power slightly, puttin un burnables back into the engine and such. as far as exhuast goes, straight pipe nif for a week or 2 just to enjoy one of the loudest things ya ever heard, but it gets old fast. glass packs are the most common, but never heard on with a flowmaster either. and it wouldnt hurt to turn the pump up a smidge now just get the little bit of oomph and better driveabilty. and long time no see mt

[choptop]

Awesome video and information from all. Thanks alot guys. I havent started on it yet, but it is patiently waiting on me in the shop.

[grayblazer]

The biggest benefit power-wise with going to a J-code intake is that it allows you to turn up the IP a little more since it allow more air in. I did this mod over the summer and it made a pretty noticable difference in overall power and throttle response.

For exhaust I have had the stock pipes with glass packs spliced in, all new pipes with some sort of Midas brand "Rino" mufflers, and now Flowmaster 40's. All sounded good and many people commented on all mufflers, including saying they did not even know it was a diesel until you got close enough to hear the engine rattle. The Flows were definitely the loudest. There is no diesel "rattle" sound that comes through the exhaust. I would recommend upsizing to dual 2.5's or a single 3". If a turbo is definite then you would be able to reuse a good portion of a 3" of it once you install it.

[choptop]

Thanks guys, Im hoping to start soon, just have to get caught up at work first.

[mtjasper]

everything mt said is true. egr does hurt power slightly, puttin un burnables back into the engine and such. as far as exhuast goes, straight pipe nif for a week or 2 just to enjoy one of the loudest things ya ever heard, but it gets old fast. glass packs are the most common, but never heard on with a flowmaster either. and it wouldnt hurt to turn the pump up a smidge now just get the little bit of oomph and better driveabilty. and long time no see mt
Just seen this post, how ya doin kody? aint seen you at the place in a while, stop in and say howdy for ol timesake

[ascates]

I like this, shows plenty of potential. I would like to see an 86 ext. cab customized.

[Koots]

Blocked off the EGR port on my K5 and it felt like i got a 10HP increase from it...before it would blow black smoke under load and i could barely get it past 100km/h...after blocking it off, with no other modifications, i had no problem accelerating around and well past 100km/h. I'd suggest a single plane j-code manifold, HMMWV headers, single 3" or 3.5" exhaust and turn the pump up a 1/8th turn.

If you decide to get a pyrometer (which you should regardless), then you could throw more fuel at it as long as you stay within certain temperature range. Seems that 1100 is the number you shouldn't exceed.

The advice given here is all good though.

BTW, post up the pics of the other extended cabs!

[Rye 21]

Argh why are there non of these trucks up north? You have managed to put two of my favorite OOBS's in one pic... nice score, the truck looks clean and straight

[Quad racer #212]

thanks for the info

[Coburn]

How much would it cost me to buy one of those OOBS EX cab trucks from ya?