[Collinsautomotive]

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

 

[Orr89rocz]

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.

 

[RCM Racing engines]

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.....

 

[RCM Racing engines]

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...

 

[GNon18s]

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.

 

[Turd Feguson]

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.

 

[Collinsautomotive]

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...

stock 454 tbi is roughly 600cfm iirc, the holley is just a tiny bit bigger, its just that they can run a shit ton more fuel pressure like 60 psi which gives a HUGE gain in injector output and the regulator is adjustable, just upgrade to the Vortect intake pump

 

[Collinsautomotive]

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.

 

[Yoyodyne]

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.

 

[dfarr67]

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.

 

[m120x-2]

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

 

[Rapidray]

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

 

[Collinsautomotive]

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.

good heads and a ported intake manifold with a upgraded throttle body will actually get better fuel economy due to superior fuel atomization with the tbi

 

[Collinsautomotive]

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

with 1989 being mark IV, vortec heads won't work for him, so edelbrock heads it is, which is nice, a upgraded tbi unit, intake, heads and exhuast and it'll make wonderful grunt and tow well.

the stock TBI fuel injection system is plenty adequte with a few upgrades.

 

[DualQuadDave]

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

 

[Rapidray]

with 1989 being mark IV, vortec heads won't work for him, so edelbrock heads it is, which is nice, a upgraded tbi unit, intake, heads and exhuast and it'll make wonderful grunt and tow well.

the stock TBI fuel injection system is plenty adequate with a few upgrades.

You got me there Collins, my bad! forgot the year cutoff on GEN V which was only 1991 not 1989.

The Edelbrock (Edelbrick) 60496's are the best option there for about a $1000 dollars a pair complete. And the 111cc chambers will raise the compression.

 

[Screwblower]

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

 

[dfarr67]

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.

 

[dfarr67]

stock 454 tbi is roughly 600cfm iirc, the holley is just a tiny bit bigger, its just that they can run a shit ton more fuel pressure like 60 psi which gives a HUGE gain in injector output and the regulator is adjustable, just upgrade to the Vortect intake pump

GM TBI is easy to add a machine screw to turn up the pressure. I think is 94/95 GM had the higher pressure TBI so his pump may have some juice.

 

[dfarr67]

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.

For my 89 truck with 7747, Edelbrock ran 4/4 injectors, my only problem was poor splicing but I heard others had driver problems. DynamicEFI makes a pnp 7747 among others that is specially modified with a 'port' mod, been runningit for years with several sets of different injectors- my tuning skills are crap however.