454 tbi questions

[66gmcguy]

Hello folks. I am contemplating swapping a 454 into one of my trucks, but I would like to run a factory TBI setup on it. My friend has several 454s he's willing to sell but I believe they are all from pre TBI trucks. If I bought one, could I just install a TBI intake, distributor, knock sensor ETC on it, or were the TBI engines different? The only real change in big blocks that I'm aware of is when they went to a 1 piece rear main seal in 1991. I am wondering if I bought an engine from something as old as maybe 1981, the TBI stuff will be a direct swap onto the engine. Thanks

[THI]

1987 through 1990 454 TBI engines were identical to the earlier 1980's engines, including the camshaft. Their intake was a q-jet carb intake with an adapter and the heads were the same Peanut Port heads used on the 1980's trucks and the blocks used a block-off plate where the mechanical fuel pump would go.

1990 changed things a bit not only with the 1-piece rear seal, there were no provision for a mechanical fuel pump and the intake was changed to a one-piece cast iron and the cam was changed in 1994 to have a little more lift and duration, but still small for a 454. As for the intake, the factory 1991-1995 was a cast-iron version very similar to the Edelbrock aluminum replacement for the 1987-1990's - in other word if you can find a 1991-1995 intake, it will bolt up to the earlier engines and flow just as well as the aftermarket intake.

[Ziegelsteinfaust]

Wouldn't a Holley Sniper, MSD Atomic, and or FITech tbi system be superior?

Plus allow for much more defined tuning to accommodate future engine growth?

The MSD is carb legal on quite a few years if you need that.

[Corts60]

Originally Posted by Ziegelsteinfaust

Wouldn't a Holley Sniper, MSD Atomic, and or FITech tbi system be superior?

Plus allow for much more defined tuning to accommodate future engine growth?

The MSD is carb legal on quite a few years if you need that.

X2. I would go aftermarket fuel injection. TBI is far outdated and trying to cobble together a TBI system from spare parts most likely would only end in frustration.

[LT7A]

The TBI setups are definitely performance limited. But for reliability, I don't think you would find an aftermarket system that could surpass it. That's what the performance oriented shop near me says, and that's what many of the threads on here seem to indicate when you hear the difficulty of getting those aftermarket systems to run right. I don't have any experience with the aftermarket systems, but I have run a TBI system trouble free for 29 years and 235,000 mi. The aftermarket systems are definitely more tunable than an old OBD1 computer. But if you put the fuel system together aware of its limitations, it should give you years of trouble-free service.

[66gmcguy]

Originally Posted by LT7A

The TBI setups are definitely performance limited. But for reliability, I don't think you would find an aftermarket system that could surpass it. That's what the performance oriented shop near me says, and that's what many of the threads on here seem to indicate when you hear the difficulty of getting those aftermarket systems to run right. I don't have any experience with the aftermarket systems, but I have run a TBI system trouble free for 29 years and 235,000 mi. The aftermarket systems are definitely more tunable than an old OBD1 computer. But if you put the fuel system together aware of its limitations, it should give you years of trouble-free service.

That's exactly what I was thinking. I've run Holley Sniper kits and a FiTech kit on a few different engines and have had nothing but problems with them, to the point where I'll never buy one again. I am going to keep the engine stock. I just want a 454 for better towing ability in the mountains were I live.

[66gmcguy]

Originally Posted by THI

1987 through 1990 454 TBI engines were identical to the earlier 1980's engines, including the camshaft. Their intake was a q-jet carb intake with an adapter and the heads were the same Peanut Port heads used on the 1980's trucks and the blocks used a block-off plate where the mechanical fuel pump would go.

1990 changed things a bit not only with the 1-piece rear seal, there were no provision for a mechanical fuel pump and the intake was changed to a one-piece cast iron and the cam was changed in 1994 to have a little more lift and duration, but still small for a 454. As for the intake, the factory 1991-1995 was a cast-iron version very similar to the Edelbrock aluminum replacement for the 1987-1990's - in other word if you can find a 1991-1995 intake, it will bolt up to the earlier engines and flow just as well as the aftermarket intake.

Thanks for the info sir!

[LT7A]

If you don't mind, let us know what you decide to do. I would like to follow along. Because working within the parameters of an OEM setup, I could still think you can have a good strong runner. Haltech out of Australia seems to do a great job of putting together ECUs and providing support. I've thought it would be cool to use one of theirs on my TBI truck and make it possible to tune it beyond what OBD1 can handle, and not have to literally burn new chips. But that kind of messes with the out of the box bulletproof-ness. But it would be great to hear how your system works out, and a conservatively built 454 could still be a strong runner.

[44th Miss Inf]

Use a Vortec (ep381) fuel pump instead of the tbi (ep386) pump. The tbi pump barely puts out enough volume for the 350.

I’ve been doing this since about 2000 with excellent results and wakes up the 454 a bit

[66gmcguy]

Originally Posted by 44th Miss Inf

Use a Vortec (ep381) fuel pump instead of the tbi (ep386) pump. The tbi pump barely puts out enough volume for the 350.

I’ve been doing this since about 2000 with excellent results and wakes up the 454 a bit

I see. Are there any other mods I have to do to install that pump? Like a different fuel pressure regulator, change the tune, etc.

[44th Miss Inf]

Originally Posted by 66gmcguy

I see. Are there any other mods I have to do to install that pump? Like a different fuel pressure regulator, change the tune, etc.

No other changes needed. Regulator is in the throttle body unit itself and will keep the pressure the same as the tbi pump, but the Vortec pump puts out a higher volume. I’ve never had on issue with the factory selector valve, nor lines

[66gmcguy]

Originally Posted by 44th Miss Inf

No other changes needed. Regulator is in the throttle body unit itself and will keep the pressure the same as the tbi pump, but the Vortec pump puts out a higher volume. I’ve never had on issue with the factory selector valve, nor lines

Ah I see. Thanks for the tip. Do you know if I could take any year throttle body (1987-1995) and put it on the engine, or are there certain years I need to look for? Obviously it has to be from a 454, but I am wondering if there are differences in bolt patterns or anything like that over the years.

[Wwes]

Originally Posted by Corts60

X2. I would go aftermarket fuel injection. TBI is far outdated and trying to cobble together a TBI system from spare parts most likely would only end in frustration.

Nonsense. I did this for a 350, was told it wasn't possible, but it's working fine.

OP -
You need a 454 TBI unit, no difference in bolt patterns or years that I recall.
I wouldn't use the Vortec pump either, lack of fuel flow won't be any problem for you. Build it just like the factory did cause it worked fine back then.

[44th Miss Inf]

Originally Posted by Wwes

I wouldn't use the Vortec pump either, lack of fuel flow won't be any problem for you. Build it just like the factory did cause it worked fine back then.

If you do any kind of towing with it, there is definitely a difference between the Vortec pump and the TBI pump.

If either of you was closer, I could borrow a buddy’s truck that has a Vortec pump in one tank and a TBI pump in the other. Loaded, it is night and day difference

[LT7A]

I would definitely step up the pump. On my 350, I went to an EP 377 which was the big block pump at the time. I know on the 350s the stock pump doesn't provide all the pressure they could use. My truck definitely benefited from it with a crisper throttle and better acceleration. With 235,000 mi, it's a much quicker truck than it was when I bought it brand new. Other mods as well, but the TBI is improved by percentages when you let them breathe and get them all the fuel they can use.

[THI]

I helped my brother put a Vortec 7400 engine (Gen VI) in an off-road 1993 K1500 Blazer, upgraded to the Vortec pump and burned a chip to delete the EGR (Gen VI heads do not have an exhaust crossover). He used an aftermarket carb intake and plate adapter and long tube headers with a heated O2 sensor - everything else is stock including the 454 TBI unit with 80# injectors - runs great and is very reliable. With the regular TBI pump he was starving for fuel, runs the current set-up around 12 psi

[S10Fan]

I installed a TBI setup a year ago on a stock 350 crate motor. The motor is in my 50 Chevrolet (car), I LOVE the TBI setup I have (PFISYS.com). The prices have gone up since I bought mine. The kit came with everything I needed other than fuel line. The kit is loosely copied from a 1990 Chevrolet pickup with a 350. I did buy a spare fuel pump to carry when I travel, hey, ya never know. LOL

I have friends that have used both the Sniper and FiTec, reviews are all over the place. Installer ability needs to be considered as well. The one constant between the two seems to be tech support, Holley's is great, FiTec, not so much.

Good Luck! This old school Carb guy is sold on EFI.

[Corts60]

Originally Posted by S10Fan

I installed a TBI setup a year ago on a stock 350 crate motor. The motor is in my 50 Chevrolet (car), I LOVE the TBI setup I have (PFISYS.com). The prices have gone up since I bought mine. The kit came with everything I needed other than fuel line. The kit is loosely copied from a 1990 Chevrolet pickup with a 350. I did buy a spare fuel pump to carry when I travel, hey, ya never know. LOL

I have friends that have used both the Sniper and FiTec, reviews are all over the place. Installer ability needs to be considered as well. The one constant between the two seems to be tech support, Holley's is great, FiTec, not so much.

Good Luck! This old school Carb guy is sold on EFI.

Man I had no idea anyone was making full aftermarket TBI kits! That is awesome.

[MARKDTN]

I looked on car-part.com and in California you can buy a complete '91 up 454 for less than $1000. Add a harness, ECM, and an '87 fuel tank with a new pump and go. Change the hoses to EFI hoses and clamps. With the right exhaust and mounts, it's a bolt-in swap. I put a Corvette Tuned-Port 350 in my '83 K20 and I love it. If you buy a whole engine, everything already goes together. You don't have to worry about port mismatch. You will have a TBI unit and a distributor. If you tried hard enough you could probably get the ECM and harness together with it. The factory TBI harnesses are very simple. I like using as much factory stuff as possible. Parts available in any parts store in the US. Could take to a dealership in a real pinch. You may not be able do that with an aftermarket system.