I have a 91 z with a 305 tpi and im looking to swap in a 350 tpi, my question is what year engines should I be looking for? Any of them better than the other? I found one out of a 88 but I dont know if I should keep looking elsewhere. Were certain years roller or nonroller cam? I dont know about all the differences through the years. Any help greatly appreciated, Thanks, Randy

 

'87-up in passenger cars were roller lifter cam.

There really isn't much difference between 350's from that time up. The bigger difference was type of injection. The heads in trucks and passenger cars with TBI were not as good as the TPI heads.

Otherwise, it doesn't make difference.

 

A stock 91 305 would be a Speed Density EFI, the 88 a Mass Air Flow system. Different Harness and ECM.

 

There is absolutely no reason to change the TPI system currently in the car. The hardware is identical, small details like injectors and PROM are all that would be changed for the '91 system to work on the '88 engine.

 

Well, after talking with the guy that has the motor he has informed me that it is a non roller block, so it must not be out of an 88 as he said. The motor is currently in an s-10 with the tpi unit still on and running very good, and will be sold with everything from intake to pan, Im just a little worried about it bieng a non roller motor, although I hear its easy enough to convert it using a cam stop and the roller cam etc.. or should I just pass it up and look for an 87 up motor? Were the flexplates the same? What about rear seals? I want a direct bolt in for the car. Thanks alot, Randy

 

'86-up were one-piece rear main seal. 2-piece is a simple matter of making sure you have the right size flexplate (153-tooth).

'87-up had the center two intake mount bolts on each side at 72 degrees. If it has a TPI base, then it already fits. Put the rest of your TPI hardware on that base.

 

if you're trying to avoid confusion and you have a desire to retrieve your motor from a donor car, as they say, 86 or 87 and up have roller lifters. typically, the latest years of 350 tpi 3rd gens had more power. 90, 91 and 92 L98s had 245 hp and 345ft-lbs. 89 had the same torque, but 5 less hp. All quite respectable swaps.

 

There is no "or" - it's 87-up.

 

Well, apparently the motor isnt even out of a thirdgen, its out of an 87 or 88 truck that was orriginally tbi, and the guy just put the tpi induction on it. Any advice on where to go from here? I know the heads arent as good, and its a non roller block, anything else? Can I still use all the same engine parts ie.. roller valvetrain etc.. flexplate the same? rear main the same? Thanks alot guys, Randy

 

Not at all surprising.

You can use your 305 heads. They'll be much better than the truck heads. With 1.94" intake valves they're even better.

Some of the truck blocks were machined for the roller set-up, most were not. Only way to know is to open it up and see. If not, then it's not worth it to try to go roller.

Same flexplate, same type of rear main seal.

 

I think im going to pass this one up and just keep looking for a 87 up 3rd gen 350 as performance is what im after, I dont plan on keeping it stock for long and I like the idea of the roller valvetrain, I am after a mid 12 sec timeslip. Thanks alot guys, Randy

 

What would be the better engine as far as performance goes? A roller 350 or something like this truck motor, (assuming I at least use my 305 heads)? What are some opinions? Im having a bit of trouble finding a roller 350. Im assuming the truck engine has 4 bolt mains which would be stronger, What about an older vette engine like the 88-91? I am now not sure which way to go but would like to get under way while the car isnt going to leave the garage for a couple more months. Opinions would be great. Thanks Randy

 

Look for a roller passenger car motor. Try and stay away from truck 350's... some were 4 bolt, but the usually have crappy heads and are flat tappet.

 

Wich passenger cars came with roller 350's?

 

'87-'92 3rd gen f-body, '87-'92 B-body (Caprice, Roadmaster), '87-'91 Vettes.

Ever consider a GM shortblock? The L31 is roller-prepped. http://www.sdpc2000.com/catalog/514/...e-Assembly.htm