Hey everyone. I have a 86 z-28 thats been sitting around for a while. I originaly took the ecm and harness out of it, and the fubar'd LG4, and the 700r. I replaced them with a early model block with some goodies and carb, with a th-350 out of a '79 Z. Well I never got it running due to the fact that the balancer had been spun, and was throwing off the timing. I have now sold that motor and was wanting to maybe buy a used 350 TPI and harness from a donor car, or maybe buy a mild long-block and put the TPI on it. What do you guys suggest and is there any problems with what I have in mind? Also which year model(s) ECM/harness/motor combo is better?

Sorry for being so long and all. Thanks for any replies!!

 

The '86-'89 MAF TPI systems are the most engine modification friendly. They are also the most power limited. '89 doesn't have the cold start injector.

'90-'92 SD system is tweaky to any engine modification, but PROM tuning friendly.

There aren't any particular problems with your approach, but you are in for more modifications than you would be if you just put another carb'd setup in it. People on this board and eBay often have complete engine/transmission/ECM/harnesses for sale.

Another approach to consider since you have it all torn apart anyway is to go with an LT1 setup.

 

What modifications do you speak of? I assumed (you know what that means) that it would basicly be running the harness through the fender/firewall, and connecting it to the just-put-in motor out of the same car. Now I know thats a LOT easier said than done, but other than the normal pita problems, is there something else? I also still have the 700r4 that was originaly in the car. I could just put that back in if that helped. Thanks for the quick reply!!

 

Fuel supply, mostly. The EFI setups had an in-tank electric pump and wiring to run it, including relays and switches. Carb (typically) just had the mechanical pump on the engine. The fuel lines from the tank to the engine are also different.

Yes, you can use the TH700. The TPI would have to come from a donor car with an automatic in order for the torque converter lockup function to work. You could set it up to operate like a non-computerized system in that case, though. (Although, all factory 350 TPI's had an automatic.)

 

Thanks again