ls swap

but seriously im not sure other than longtube headers and exhuast that would be cost effective

 

Pretty much headers with a decent exhaust and a decent air induction system, beyond that is a jump. You can typically bump base timing a degree or two, and shim the fuel pressure regulator to up the pressure a tad. - The heads are a major restriction and cam on the Gen V TBI BB's, so much so that they give up power & efficiency everywhere. Some old 781 ovals, the Gen VI Vortec ovals, or most any aftermarket oval port head will make more torque as well as more hp.

 

Edelbrock 60439 heads are designed to raise the compression on those motors.

 

Whats the budget?

 

Single best mode is a better exhaust system. I personally hate headers on a tow rig. It will just eat sparkplug wires.

Next if you have the money would be a bump in compression. A local shop can do a cheap port and mill job or go with the edelbrock heads. I would also switch to the edlebrock TBI intake.

This year 454 truck are the simplest to work on and will last for ever. You will never make the power you want out of this combo. You need to learn to live with it or start looking into a repower or upgrade to diesel.

By far the best upgrade would be to do a 8.1liter swap.

 

This is what I have in mine......it works fantastic.....

https://www.jegs.com/p/Chevrolet-Performance/Chevrolet-Performance-HT502-502ci-406HP-Truck-Crate-Engine/760849/10002/-1

Mine was a kit deal a few years back that had the engine with all supporting
pieces.....fuel pump and regulator, trans recalibration kit, bigger trans cooler
and a few other goodies.

The 8.1 liter deal is also a good way to go.....to get that 454 to do what you want
you will have to do major upgrades and it will still be mediocre.

Simpy cannot beat cubic inches for this.......My 502 gets 9-13mpg depending
on what I am doing with it.

 

Our motorhome is an '01 30' Winnie with the Vortec 454/4L80E. With headers/decent exhaust(big mufflers, so it's still quiet), and just a well flowing/well insulated air intake system it manages 8-9mpg with a trailer toad and our loaded 28' enclosed. 69'7" OAL and 12 tires on the ground, it pulls fine in overdrive at 70-75mph and not many diesels doing much better mileage wise with that kind of rig.


The TBI motors are choked pretty bad, but definitely still respond well to the simple mods noted earlier. - Our previous mh was a '95 32' Gulfstream, TBI 454/4L80E and it towed our 24' enclosed at 65-70 in overdrive reasonably well.

 

I just tuned one locally. 95 tbi 454. The guy did a different intake manifold with an adapter to keep the tbi. Small comp cam, i believe 218-224. Long tubes and custom dual 3” exhaust. It seems pretty strong. Runs great. Did not dyno, just stteet tune with wideband. It required more fuel in the tune so it makes more power.

Never been in one stock so idk how much of an improvement it was. He said it feels stronger tho. Have not towed the trailer with it yet but truck seems like it should handle it no problem. It sounds awesome tho

 

Holley makes a 670cfm tbi bolt on upgrade, tue Edelbrock tbi intake amd the heads mentionded above even with a stock camshaft, a good quity set of headers and free flowing exhuast, will net around 80hp 100 lb ft and tons of tq while not even remotely effecting driveability.

I used to do allot of these types of engines in duallys,campers etc amd while you cam upgrade the camshaft, it's not really holding the engine back nearly asuch as the heads intake and TB are.

 

as for tunning a copy of tunercat amd some parts from moates.net amd some reading around some forums and it's easy to tune.

 

If you are trying to get torque up in a 1992-19996 454 TBI engine in a 3/4 ton truck on the CHEAP! your actual changes are somewhat capped but you can make a pretty substantial increase in torque output between 1500 -4500 rpms, WHICH IS WHERE YOU NEED IT FOR TOWING! PERIOD!

The L29 in your year TBI was a 230HP (sick) and about 375lb/ft(sick) engine.

Your static compression is just a shade under 8.0 to 1 (sick).

This is a recommendation as I have done quite a few upgrades on 454 truck engines for towing including 2 for my personal boat towing uses and THEY WORKED VERY WELL!

First things first, GET THE COMPRESSION UP! You need to buy a pair of GM iron Vortec part number 10141279 - 1998-2000 heads. They have a 99cc versus 121cc combustion chambers and with a good .041" head gasket will get your compression up to about 9.5 to 1-WHERE IT NEEDS TO BE! You can find these heads new in the box from GM through resellers on Ebay for example for about $500 per head complete!

Buy the electric in tank fuel pump upgrade pump from Summit-about $70 The stock pump especially with age will not pump enough pressure and volume to keep up with the added power some minor changes like this will produce!

A good towing spec. cam for this use is a Comp Cams part #11-412-8 grind # 266HR-12.Available from various suppliers for about $275 -300 per cam.
This cam will produce the most torque between 1500-3800 rpms which is where you want it for towing. With this cam you will be able to tow in many areas in OVERDRIVE between 55-70mph! This is ideal for towing and mileage!

You will need some chip upgrades on your trucks ECM to get the TBI system operating perfectly but their are several shops and guys doing these TBI tuning upgrades.

TBI secret sauce claims and intake manifold changes won't get any more torque in these ranges and will be a WASTE!

Adding headers (long tube only- shorties junk) and a better exhaust pipe and muffler adds will help slightly they are more expensive probably adding another $1000 for a complete long tube /pipe/muffler upgrade.

The three upgrades above will take power up to about 400-425 HP and torque will peak about 3600 rpms @ about 480-500 lb/ft.

TORQUE IS WHAT TOWS BEST NOT HORSEPOWER AT HIGHER RPMS!

If you truck has big knobby oversize tires for that big truck cool look, then remember they will kill highway speed towing mileages LIKE GODZILLA SUCKING FUEL THROUGH A 12" STRAW!

If you want to have decent highway speed mileages, lower noise levels and nicer handling then put on a good set of light truck highway tread radials, keep them inflated to 45lbs minimum and they won't look as cool but if your towing longer distances you will soon realize that was one of the best changes you ever made!

Follow good recommendations like this will work and you will be happy. Taking to many half baked ideas off of posters on the internet who many of which have never owned, properly modified and towed with a Chevy 454 TBI truck like I have for years are BLOWING TO MUCH SMOKE UP YOUR BUNG HOLE!

 

ummm, there some cooling passages difference between in the cylinder heads between Mark V and gen 6 mark 6, so not sure where you are getting your info, but tread carefully here. if you have the work around please post it. last I looked into it, the edlebrock heads were a better deal overall.

 

Gears.

 

Gears are very important however most 1992-1996 C2500 454 trucks I have used and seen come standard with a 410 gear and that seems to be the best overall with the 4L80 overdrive tranny for towing.

 

My truck was 4.10/4l80e. Now it's 4.88/4l80e. 35" tire. It works better for me. Doesn't kick down so often to go up every hill on the highway. My gas mileage improved slightly because my foot is not in it so hard all the time.

 

Mr. CollinsAutomotive

Thank you sir, I will try to tread lightly on you here.

The OP's engine in his truck is a 1994 Gen V 454 engine. The Vortec GEN VI GM heads I recommended and have used a many times myself fit the GEN V blocks just nicely with any GEN V -GEN VI head gasket set. The tops of the GEN V and GEN VI blocks are identical on the decks and openings.

If we were trying here to put GENIV heads on this GEN V block then sealing the water passage openings along the top edge of the block would not seal properly and could leak into the lifter valley.

Luckily this is not my first rodeo working on chevy big blocks, about 45 years worth!

Respectfully
Rapidray

 

thats what it was, theres some goofy shit between 1988-1998, that said, are the vortec heads really that good ?

 

There was a older Edelbrock MPI conversion kit that worked well for my 350, but would have worked even better with a tune able ecu. DynamicEFI may have a pnp product for this year.

 

Got a question Rapid, would the OP benefit from ditching the factory TBI setup and changing to one such as FITECH or Sniper to go along with all the changes you've recommended? Is the factory TBI the weak link per se and if going to an aftermarket injection what things should be changed from your previous post? Looking at a 1 ton truck myself that would need these upgrades. Thanks

 

Tbi can be an issue once you get into big power. Trouble is finding an injector to feed it. I believe the 454 trucks got two 80 lb hr injectors at 30-35 psi pressure

Other than that, simple mods like discussed here, i wouldnt change it. The factory 7427 ecm in the 94-95’s is fairly easy to tune and very capable ecms.

 

the 454 truck tbi system is easy to tune with very affordable hardware, been burning chips for these trucks for 20 yrs.

the stock tbi leaves a bit to be desired, parts are scarce, throttle shaft leaks, injector issues etc.mostly age related trouble.


https://www.jegs.com/i/Holley/510/5...BRBBEiwA8d0Q4tlMLXe-q-vg5NyFuaJGKraCO5iys6fOoWZ5rUiWEaprYxQ25gzttBoCxlIQAvD_BwE

 

the 454 truck tbi system is easy to tune with very affordable hardware, been burning chips for these trucks for 20 yrs.

the stock tbi leaves a bit to be desired, parts are scarce, throttle shaft leaks, injector issues etc.mostly age related trouble.


https://www.jegs.com/i/Holley/510/5...BRBBEiwA8d0Q4tlMLXe-q-vg5NyFuaJGKraCO5iys6fOoWZ5rUiWEaprYxQ25gzttBoCxlIQAvD_BwE

I thought the 454's had an 800 cfm TBI...
Mine looks bigger then that.
Only issue I had was injectors, I put 2 new GM ones in and it had been great.... My shafts are tight, but mine only has 128,000 on it...

 

I have a 93' chevy Suburban with the 454 in it....
The single biggest thing I did that made a difference without going In the engine was Long tube headers and full 3" dual exhaust with good flowing mufflers and no CAT's, made a huge difference in power, I Also turned the timing up to about 8* with the brown jumper ire under the dash unhooked to set it.....
Night and day difference in power and MPG.. I did have a Hyper chip stage III in it and it hurt MPG and was rich all the time, so I took it out, these engines are a joke at 7.6:1 compression and .390 lift on the cam....

I Ran into a guy at Super Chevy one year that had a 93' pickup with the same engine in it and it ran high 13's,
I went to check it out expecting a carb and all the goodies, it had the stock TBI on it, he rebuilt the engine, got the compression up to 9.8:1 compression, put older 781's on it ported, bigger valves and a hydraulic roller cam
different intake as well.. I ask him about the TBI, he said it's the stock ECM with a Hyper chip in it...LOL
said it'll support up to 500 hp all day long, come to find out, he used it to tow a 24 ft enclosed trailer with his race car there and was racing both, said it towed like a dream and had power out the ass as he put it.LOL

I will toy with mine someday, I do have a 502 450 hp I may put in it and see how that runs.....

 

What about a goofy TBI/Vortec hybrid?

TBI long block.....Vortec top end (heads/long runner manifold)...mild cam....long tube headers....still using the TBI PCM......bank fire the fueling and use the TBI distributor.

1 "low impedence" injector driver should be able to fire 4 "high impedence" injectors depending on the max current the driver can support.

This of course is assuming the OP has access to chip burning equipment/tuning

Although at that point it might be easier to buy an original vortec truck and sell the existing vehicle.

 

4 16 ohm injectors wired parellel is a 2.5 ohm load, the drivers in the ecu can handle that. Some of the later ECU's had issue with impedence mismatch causing wierd injector driver behaviors I never figured out. Something in the way they implemented the peak and hold functionality, tried changing sense resistors drivers etc, never could get it to work right.

 

I'm following with much interest, because I'd like to build something similar for my '89 TBI truck. I have a nearly new Edelbrock MPFI setup, would that flow enough air with the TBI throttle body to feed a 496 to 4000 rpm for towing? Using the MPFI deal would allow use of the OE computer which could save a lot of work or $. It has the larger injectors intended for use with a 502, that's why I have it, it didn't work right on a 454.



I have 2 sets of heads on hand, a pair of 3989241 and a set of Truck 3983136 castings. Both oval port, the truck heads are sort of closed chamber, CCs unknown ATM. Would either of these be a good choice?



Would the MPFI small port manifold work OK with oval port heads? If not, would a larger oval port manifold with bungs for the injectors work with the TBI TB or would a larger TB be needed?



I have a NOS set of Doug Thorley long tube Tri-Y headers for the truck - single outlet for the cat.

 

Yoyodyne:

Not sure what you are thinking here but you need to get back to a better starting idea.

First none of those BBC head casting numbers are correct?

Second if you are going to spend that much money and trouble trying to put an old technology "Edelbrick" semi -efi system and remain with a stripped down TBI throttle body only you are wasting money and not getting any real towing "bang for your buck"!

I would not put any money in to old iron BBC truck heads done right when you can buy a nice set of new or completely reworked Vortec small chamber heads for less than you will put making an old set of truck heads work! They add compression WHICH YOUR 89 454 TBI NEEDS BADLY!

The headers would be a nice addition since you already own them.

All I can say if you're a wise man and want to make an older 1989 TBI truck work for TOWING, keep it simple, follow something like I laid out on this post and don't try to get torque and towing performance putting all sorts of big dollars into expensive EFI systems and engine conversions and builds, when the cost of these types of conversion would probably exceed the value of the truck.

JMEXPO

 

I don't know BBC, what about a ported set of peanut ports and a good intake- carb to TBI adapter, headers and a tune. Try GearheadEFI, Thirdgen for tunes.

 

What long tube headers would you recommend for a 1998 K3500(4X4). Will they help with the Vortec engine? What exhaust would be used. Looking for quality and ease of installing.

Don't think I have to go through state inspection anymore. Truck has been parked for a couple years but still in good shape. Thanks

 

My S/S Dynomax muffler rotted inside out. What I have is an older set of Edelbrock TES mid length headers that have lasted for years, I rebuilt the y-pipe to be efficient and exits at 3.5in, I found a S/S 'bolt in' kit from ProFlow for a 88-99 6.5 TD application is 4in full length. 4X4's plumbing is a little harder to deal with. Stainless Works Ithink makes a set and also Thorley, Stan's.

 

Yeah, the "let's do a whole alum topend" on the $5000 truck is great idea, but just not worth it $$$ per hp gained. Bang for buck, E-brock tbi intake, home port it, find a big bore TBI for it(there used to be shop that made super big ones, but I think they shutdown), chip it/tune it and 3in single exhaust w/ good plug wires. Done. The headers will drive you out of your mind w/ exhaust leaks, even with good gaskets. If there is a set of higher ratio bolt on rockers, do those too. IMO pulling the heads off is a waste of time unless you absolutely love the truck. If you do really love it, a Cummin's or Vortec swap is best $$$ spent long term

 

Yeah, the "let's do a whole alum topend" on the $5000 truck is great idea, but just not worth it $$$ per hp gained. Bang for buck, E-brock tbi intake, home port it, find a big bore TBI for it(there used to be shop that made super big ones, but I think they shutdown), chip it/tune it and 3in single exhaust w/ good plug wires. Done. The headers will drive you out of your mind w/ exhaust leaks, even with good gaskets. If there is a set of higher ratio bolt on rockers, do those too. IMO pulling the heads off is a waste of time unless you absolutely love the truck. If you do really love it, a Cummin's or Vortec swap is best $$$ spent long term

Dave gets it. I'm not building a hot rod. I need a new motor, this one leaks more than it burns. I can do a crate 502 or do a 496 for slightly more than the cost of a rebuild and use up some the the parts I already have. If I can get another 80 - 100,000 miles out of it reasonable cheaply then either I'll buy a diesel Megacab or I won't need one at that time.


The truck already has a Edelbrock TBI intake manifold (only because the stock iron manifold cracked) a 3" exhaust and other than the worn out motor it suits me just fine. Doing a Cummins swap to my satisfaction would cost more than doing this motor and I really don't want a diesel. i don't want a Vortec or a 8.1 because I don't want to have to take the truck back home to the shop where it was built when something fails along the interstate.

 

At 7:6 compression put a blower on it.
Or a small turbo.

 

Yoyodyne

Based on your last more complete information and explanation, I can give you one more simple recommendation.
Take your existing block, buy a complete 496 rotating assembly off of eBay @$1500, buy the Edelbrock RPM heads complete @975. Take the block, kit and heads with a good gasket kit to a good machine/rebuild shop and have them build you a nice 496 long block. Install a nice hydraulic roller camshaft like the number from Comp I listed earlier in the post. Install your Edelbrock Mpfi kit you already own, bolt on your headers, drop it in the truck, change the fuel pump, put a nice tune on it and you will have a nice reliable high torque engine for towing.Nothing exotic just a nice engine for towing and about as inexpensive as a GOOD BBC 496 engine can be!This engine should make an easy 475 Hp and 500 lb/ft of torque @3800 rpms. Your existing 454 probably made 260hp when newer and about 325 lb/ft of torque for comparisons.
Take those ugly old iron truck heads you have, take out a valve on each head,loop some chain thru them and use them for boat anchors!
You are going to spend about $4K to $5k doing this right with the parts you have, the machining, assembly and parts you need to purchase. If you can and will spend about this you'll do fine, if not then your kidding yourself on what you need to do. JMHO
Good Luck!