View Full Version : 5.7 vortec swap

07-21-2009, 04:58 AM
Hi everyone im not familiar with the whole fuel injected swaps in old school cars and am not that familiar with the 5.7 vortec engine either im more into imports and lsx engines.Well here goes the story my dad recently wrecked my 98 suburban (hes fine ofcourse) but anyway the trucks chasis is bent so its out to the yard it goes.Im gona take the swap out and am going to put it on a car that I havent decided yet I was thinking more of an old chevy car but I need advise what is everything I got to take from the truck for the future swap.Any info will help also any other forum that can help me out more because this site is mainly for ls series engines and cars.Thanks for looking

07-21-2009, 10:34 AM
The 5.7L Vortec engine (L31 ?) from a 98 Sub is a SBC Gen I engine that is TBI intake. Its output is 255hp (?).. You can replace the intake with a Vortec type Carb manifold or use an upgraded EFI system.

It is really nothing more than a SBC engine, It is the last of the truck SBC engiens. The Vortec Heads are a good set but are limited on the cam lift (.450 to .475) due to the springs and design of the head. With some minor mod, you should be able to get 350hp. The long block is used for the RamJet 350

It does make a nice upgrade to an older car/truck. If you are going use it in SMOG car/truck application.. you will be stuck using the TBI (Throttle Body Injection) and all of the smog equipement from the 98 sub or simluar class truck.

So, if your looking to use it in a future swap. The question is into what ?..

If older car/truck without smog requirement.. take the engine and all of it accessories, that about all you will need. Dump the TBI system and it controller, go with a carb or aftermarket EFI system. Maybe pickup a TPI system off of a L98 F-body or Corvete.

If you are just going to use the engine as a long block swap.. just the engine.

If it is for smog legal swap, then take everything that makes it run and all items that are related to the smog equipement. Intake and Controller, wiring, etc.

IMO, older car / truck without smog and change intake to a carb or aftermarket EFI system.

07-21-2009, 07:37 PM
Thanks for the info man...Im really interested in the l98 system will the intake bolt on?I know the lt1 intake wont fit,will it? okay say I use the block only will the l98 or lt1 head pakage bolt on?I was thinking of putting it in a chevelle or nova.If I decide to go this route dont I need to retain the ecu to tell the tranny when to shift?Sorry if im raming you with questions but its gona be my first old school project so im basically touching unfamiliar teritory.On the other hand ive done swaps since I was 15 so working on engines is my joy another question ive been looking at is the fact that Idk what mounts to use especially how does the cross member gona come into play with the 5.7 V I greatly appreciate all your help

07-21-2009, 10:54 PM
The TPI / L98 system are much more limited and smipler that the current Gen III/IV system, but a Fuel system is a fuel system. The TPI's system start to run out of flow around 4800+ RPM. Porting is the one way to increase flow and RPM range. There are other replacement parts (Accel, Edelbrock, etc).

You would not be able to use the LT1/4 heads as they are reverse cooling. But there is a way to put a LT1/4 intake on a L98 TPI head.. These are documented in many other forums.

As far as swapping these engines into any older car.. it is a easy if not a simple replacement.

I would suggest you go to a few of the other forom for SBC and TPI info.. Hawks3rdgen, Corvetteforum (C4 section),, etc.. You can find a lot of info on using the TPI system and upgrading.. Jagsthatruns has a good Fuel Injection book. S&P was one of the early EFI swap specialist.

but do a little research and figure out what car you want to do.. cause what yoru asking is like 40 year of working with Chevy knowledge and all.. One you have a narrowed it down a few car and engine option.. we can work on the simle things !

07-22-2009, 09:12 PM
Okay lets get some info straight here. The 96+ Vortec motors are central injection not tbi. There is a crab style injector setup in the center of the manifold that distributes the fuel to the cylinders. The pcm can be tuned using HP tuners so thats a bonus aswell. Was the Suburban 2wd or 4wd? If it was 2 then you can use the trans in the car. If not it would be cheaper to find a 2wd trans then to have the 4wd converted. If you take the motor with all the belt driven accessories, starter, transmission, wiring harness, computer and underhood fuse box, and fuel pump or buy one to use in the car. You should have pretty much everything you need. You would need to modify the harnees to get power to the proper places but it wouldn't be to hard with a wiring diagram. Good luck with what you decide.

07-24-2009, 11:56 AM
Flame, I was suggesting he convert it to TPI....

07-24-2009, 12:14 PM
Flame, I was suggesting he convert it to TPI....

Yeah but for what purpose?

07-24-2009, 03:27 PM
He would need the redesigned tpi(vortec) intake to fit the vortec heads, Scoggin Dickey sells it and it ain't cheap, plus tuning the computer and reworking the harness.... All for what, a traditional sbc?

07-24-2009, 05:43 PM
He would need the redesigned tpi(vortec) intake to fit the vortec heads, Scoggin Dickey sells it and it ain't cheap, plus tuning the computer and reworking the harness.... All for what, a traditional sbc?
It would be a bolt in swap, if the car already had a SBC, save for the fuel injection setup.

07-24-2009, 07:01 PM
the Scoggin Dickey vortec TPI intake base is $400 plus shipping. Edelbrocks isn't any cheaper.

A complete Holley stealth Ram setup for vortec heads is $5-600, but that doesn't include everything

leaving the motor alone would be the cheapest route to go honestly, followed closely by a carb swap

remember, the cam in that motor does not have provisions for a mechanical fuel pump if you decide to go carb

good luck with it