96-99 454 Vortec owners?

[N0DIH]

How many 96-99 7400, aka, 7.4L, aka 454 owners are out there??

Seems these trucks sure have a lot of potential, but seem be awfully restricted.

I have heard exhaust really wakes these beasts up, I would like to do an x-pipe in mine and build for torque and economy. My 454 is running around 12.7-13.1 mpg so far at 55-75 mph and a mix of bumper to bumper rush hour (Dan Ryan traffic) traffic. I have 3.73's now and LT245 75 16's.

My goals are to meet the 350's mileage (so far I am very close) that my 96 Burb had, if not beat it.

What have people done to them that works or doesn't work?

I am going to work on a Wait4Me tune shortly here with agressive DFCO.
Possibly 265 75 16's to help reduce some cruise rpms (we spend a lot of time at 69-75 mph...) and ??? that might help. We live out in the boonies, so cruising at 75 ends up being the norm.... Not desired, just the norm.

[bankspowered98]

I have a 98 3/4 ton with a vortec 454 in it. I have done some mods but a cam and computer tune are next. so far i have msd 6al box, blast 2 coil, taylor 8mm plug wires, tb spacer, k&n filter, baks powerpack exhaust system. runs like a top. i normally haul our race cars down the highway about 85 or so and get 14 mpg pulling 13000 lbs.

[N0DIH]

wow! I'm not alone!

I am starting to think the exhaust is the big choke. The manifolds to the muffler are very good, fat 2.25 to 2.5" dual pipes, but the muffler seems so quiet I am wondering if it is joining badly the 2 sides and causing a backpressure problem. I think true duals would be good, and an x-pipe if possible (if I can figure out how to fit it in)

You are getting better towing mileage than I get not towing. What gearing do you run? I am guessing 4.10's with the weight.

I have been pondering an custom intake plenum spacer to make for longer runners and some additional plenum area.

[thekl0wn]

I'm looking at a '98 3/4 ton with the Vortec 454 right now. It's been a farm truck since it's purchase date. It has about 70k on it, and still runs strong. It was purchased to haul ammonia tanks, and has done an excellent job stock. After a simple bolt-on cat-back Flowmaster system, it did seem to pull a little better, and get a little better mileage, plus it actually had sound!

The only thing holding me back on the truck is that it's power nothing! Base model as they come 4X4. The motor is the only thing keeping me interested.

[N0DIH]

I am happy with the power at lighter throttle, but if you are on it harder, like trying to get rpms up, it doesn't have upstairs power. I need to hook a datalogger up and read what the PCM thinks is going on. I'm betting as rpms are going up, MAP (vacuum) isn't going towards zero vacuum, indicating a restriction in airflow.

The air filter to the MAF to the throttle body has some serious bends in it, but I don't think enough to kill that much power or airflow. They will be addressed shortly though. I have only a K&N on it now. I have never run it without, so I can't really tell you how much it is helping or hurting power.

If you get it for a good price, pull the drivetrain and stick into a nicer truck and swap the other drivetrain back to the farm truck and send it on its way.

That 454 should be in good shape, I can't imagine it run hard at all.

[someotherguy]

Originally Posted by N0DIH

What gearing do you run? I am guessing 4.10's with the weight.

This is the most important question here if you ask me.

I've got a '98 C3500 dually crew cab, 7.4 / 4L80E, 4.10 gears. It's got an under-the-bed wheel lift wrecker setup, 225/70/19.5 wheels/tires instead of 16's (overall a little taller than the OEM 16" setup), Ranch Hand front bumper, all power options (not a stripped down work truck), misc other accessories.. I'm not sure how much it all weighs but I guarantee you it's heavier than just about anything you can imagine that is still a "light duty" truck. I do need to scale it so I can see just how ridiculous it is.

Only mods to the drivetrain would be a pair of Flowmasters. When I stomp on it, even from a rolling start, it jumps! So do any passengers I have with me! Also got 10ish mpg on a 400 mile all highway trip, not loaded. Put on top of all this it probably hasn't been tuned up in YEARS, and I think it still needs the injector assembly upgrade.



Richard

[bankspowered98]

I have 3.73's with 265-75-16 michelin atx on mine. On nice flat highway i will put it in od and keep an eye on the trans temp. never gets above 200. i have also upgraded the valve body and installed a shift kit so it wont hurt the trans to tow like this. but when hills come i will drop it back into drive. i love the bb power. you cant beat it. plus the design hasnt changed from all big blocks for years and years. just intake assembly. so if you know anything about older bb, you are good to go on thses. one GREAT thing is i can pass diesels all day running down the highway, occassionally i will catch one of them looking over at the banks powerpack sticker on the door. makes me laugh. the tune however is next. what plugs are you running? that makes a hell of a difference? so do wires?

[N0DIH]

what are your thoughts on the powerpack from Banks? Worth a lot in power? I was wondering how restrictive the muffler is.

I do want to fix up the intake tract to make it a straight shot and also keep underhood heat from getting to the filter.

Got any pictures of the parts of the Banks PP?

Originally Posted by bankspowered98

I have 3.73's with 265-75-16 michelin atx on mine. On nice flat highway i will put it in od and keep an eye on the trans temp. never gets above 200. i have also upgraded the valve body and installed a shift kit so it wont hurt the trans to tow like this. but when hills come i will drop it back into drive. i love the bb power. you cant beat it. plus the design hasnt changed from all big blocks for years and years. just intake assembly. so if you know anything about older bb, you are good to go on thses. one GREAT thing is i can pass diesels all day running down the highway, occassionally i will catch one of them looking over at the banks powerpack sticker on the door. makes me laugh. the tune however is next. what plugs are you running? that makes a hell of a difference? so do wires?

[Pauly]

Originally Posted by someotherguy

This is the most important question here if you ask me.

I've got a '98 C3500 dually crew cab, 7.4 / 4L80E, 4.10 gears. It's got an under-the-bed wheel lift wrecker setup, 225/70/19.5 wheels/tires instead of 16's (overall a little taller than the OEM 16" setup), Ranch Hand front bumper, all power options (not a stripped down work truck), misc other accessories.. I'm not sure how much it all weighs but I guarantee you it's heavier than just about anything you can imagine that is still a "light duty" truck. I do need to scale it so I can see just how ridiculous it is.

Only mods to the drivetrain would be a pair of Flowmasters. When I stomp on it, even from a rolling start, it jumps! So do any passengers I have with me! Also got 10ish mpg on a 400 mile all highway trip, not loaded. Put on top of all this it probably hasn't been tuned up in YEARS, and I think it still needs the injector assembly upgrade.



Richard

the Vortec big blocks run a very different injection system than the small blocks do. The bigblock injection is by far more desirable because it uses conventional fuel injectors which can be replaced with larger sizes without changing the intake manifold.

IIRC the 454 Vortec uses 24 lb/hr LT1 fuel injectors. It is rated at 290 hp and 410 lb/ft torque.

The cylinder heads are very restrictive to power production. I have seen Vortec 454's dyno at 217 hp at the rear wheels in a 1 ton truck, torque was over 320 lb ft at the wheels.

headwork along with a cam can really wake these 454's up. They are a step up from the TBI 454's which make their peak torque at 1800 rpm. They came in 230 hp 385 lb/ft and 255hp 405 lb/ft flavours.

A nice set of aluminum 502 heads woiuld work nicely in tehse trucks, or drop in 502 shortblock.

peace
pauly

[N0DIH]

I have seen a lot of people say the L29 heads (96-02 454) are some of the best kept secrets of GM, similar comments that they said on the L31 heads.

Head flow #'s I have seen haven't been bad like the L19 and L03/L05 heads. Cam is a little small, 204/209ish. Most people on TeamChevelle.com said a cam swap makes this engine a monster. The ZZ502 cam being one very popular.

Even the HT502 uses the exact same heads and cam making 338 hp and 510-520 lb/ft torque.

Being I haven't seen a "head to head" comparisson on these engines I can't really say if the real reason these 454's are dogs compared to what they should be.

Honestly, the #1 reason I wanted the 454 over the 350 was the injectors. I can't run E85 in a 350 at all without an intake swap. The 454, easy. A set of 44# injectors on stock PCM tune and you are set for E85. Add some additional timing and you should have it running pretty good. BUT, you are still single fuel. Can't swap back and forth....

[N0DIH]

There was someone who got a wait4me tune with a 5 speed 454 and ran a dyno run, I can't seem to find the post, anyone have any ideas how to do a better search?? I don't remember if it was the tech or perf forum.

[bored&stroked]

Vortec 454 heads are small ovals not peanut ports hence the "best kept secret". They pick up flow very well with minor porting and flow better then peanuts while still keeping the ports small for great torque.

[lowbird]

Put me on the list.
She is still running.

[#8trx450r]

Just bought one today, the one in my signature so I am enjoying reading all the posts on here about the 454 equipped trucks, I am ready to start buying HP goodies lol.

[wtd]

I bought one two weeks ago. A 98 reg cab 3500 4x4 with the 454. It has 95,000 miles on it and runs strong. I don't know what my mileage is yet. Fuel gauge also acts a little funny. Its still all stock. I'll probably do the exhaust sometime in the future.

Wayne

[bankspowered98]

What tune would you gentlemen suggest to get just a shade bit more power out of the BB?

[N0DIH]

I have a Wait4Me tune. Overall good. It REALLY wakes up with 93 octane. I think he is still pretty conservative with 87 octane. But still a world difference over stock. I suspect WOT power is similar on 87 octane, but much improved in the midrange and 93 octane (there is 2 octane maps, so it can react with both if the octane is pumped up)

Best $75 you will spend.

NOTE: Jesse pulls the latest tune from GM, and in my case and others with 454's, got the "Towing Improvement Program" which changes it to permanent Tow/Haul mode. You don't get lock up on the converter till 68-69 mph with 3.73's. GREAT when towing, but without, not ideal for mpg. You have to get up to 70 mphish to get "best" economy. It won't hurt, just mpg. Trans could care less. TCC lockup and unlock while towing is a setup for disaster. TCC's aren't designed for that much abuse for lots of towing. So I left mine as is.

If you can stomach 93 octane, get a 93 octane tune, or maybe a 90-93 octane tune. The performance is dramatic. If you have a Wait4Me tune, and haven't filled up with 93, go to some 0-60 times and then fill up with 93 (try to keep vehicle weight similar and octane pure as you can) and you will see some improvments. It will put the smile back on your face!

[bankspowered98]

Excellent, thats what I needed to know. I want him to possibly try and keep the converter locked up until 3/4 to full throttle for the simple fact that with the stuff I have done to the truck it actually has more torque around 1800 rather than 3000 when the converter unlocks. How long does it take for Jesse to get a tune, I am just going to order the whole computer. How do I get ahold of him.

[heavy454]

I got my wait4me tune for my 454 awhile ago but it has been great so far. for whatever reason my converter locks at about 75-76 mph instead of 69-70 and rpm's drop by about 100 and i have 3.73's. overall it was a good improvement, in addition to my other mods i really feel that my truck is now way faster even with heavy 20 inch rims than it was stock with 16's and 245/75/16's. it was kind of a dog off the line and would barely chirp the little tires, but now i mash it and it roasts the bigger tires until i let off the gas and it kicks down really hard and flies. i would love to have some port work done and a cam swap though...

[skills4lou]

I have a bone stock 98 K3500 CCLB. 454/4L80E/4:10 gears. The stock injectors where leaking at around 108K miles, so I replaced with Bosch. Better design, but the same rating (19lb/hr). It came with the factory HD air cleaner (great big round sucker) and true dual exhaust. Right now it has glass packs, but that's gonna change soon.
I've never run it down the road empty, seems I'm always hauling something. Last big run was crammed full in the bed and towing a car hauler with minivan, about 14K lbs all told. I got 10-11 the whole trip. Around town I get the same. Lately it's been hesitating a bit, so I think it's time for new ignition parts. My truck doesn't feel restricted at all, when I step on it the truck just jumps. No problem roasting tires if I'm not careful. At this point I don't really plan any big upgrades other than ignition. Bankspowered98 has pretty much what I'll be going to.