Hiball8

I have a 1990 formula 350, the engine threw a rod I bought the car this way. I was just wondering if a 85 corvette l98 stock with 60k would be a good replacement engine or should I get the l98 in mine rebuilt, no computer for the vette motor would mine work or need one for a 85 vette?

itsMikey

would be a good swap
not sure on the computer

fireturd350

iTrader: (8)

I think I can cover most of the possible differences I'm not sure exactly about the Y-bodies though.

Corvette being an '85 may have the cold start injectors yours did not.
Corvette is probably a MAF and yours is a Speed Density.
Corvette may be a 2 piece rear main seal yours is a 1 piece.
Corvette has aluminum heads yours are iron if OEM. (nice upgrade)
Corvette oil pan probably won't fit due to it not being for an F-body chassis.

Quick things I would recommend:
Swap intake (lower, upper, pelnum, rails, injectors, TB... etc) over to the new motor. I imagine since it's L98 yours will bolt right up. You'll need to use your brackets and some sensors on the corvette motor also. That should be easy enough to swap over. That should allow you to use all your original sensors hopefully. You shouldn't need any computer changes that way either. As for the oil pan you'd have to verify corvette is a 2 piece and then probably find an older 2 piece oil pan from an F-body.

fireturd350

iTrader: (8)

Yep just verified via Autozone's website the '85 is a 2 piece rear main seal.

It also looks like the '85 Corvette was also a MAF setup.

87WS6

iTrader: (1)

Honestly swapping an early L98 into your car would be a step backwards. The ECM is more primitive and there is less aftermarket support for it. You need a block from a 1987 car or later at the very least if you want to save yourself some headaches. Then you'd at least get the 1 piece rear main seal block and aside from that you could keep your stock TPI hardware and just swap the block itself over. As for not having to reprogram the ECM of your car to use the 1985 L98, I'm not so sure. I don't know what if any effect the flat tappet cam would have on your ECM. The cam specs are undoubtedly different beyond their types.

Corvette vs. 1990 Formula 350

• 1985 Corvette L98 uses a 2-piece rear main seal as opposed to a 1-piece.
• 1985 Corvette L98 uses a flat tappet camshaft instead of a hydraulic roller.
• 1985 TPI ECM is specific to that year. I believe the wiring is too.
• 1985 TPI setup uses a 9th injector for cold starting.
• 1985 TPI is MAF based while the 1990 TPI setup is MAP/Speed density.
• 2-piece rear main seal blocks use a different flywheel/flexplate bolt pattern.

As for the aluminum heads, I am not sure that the 1985 car used them. Were all Corvette L98's equipped with aluminum heads or just some years? I thought 1985 cars had iron heads.

Hiball8

Thank's for all of the insight guy's, I am just getting into redoing a car and assumed with them both being a L98 they were basically the same, sounds like this 90 L98 is a good motor, that being said I will look for a later year one that is from a f-body. Or pull this one out see how bad it is and get it checked, and rebuilt.
Thanks again for all the info!!!