I have an 88 IROC, auto, L98. I want to put the L98 in a 5speed 305 z28, between 1990-1992. What exactly I'm i going to have to do with the computer since the 350 computer is for an auto and the 305 computer is for the 305? Is there any way around a custom chip? And if i use the 305 chip on the 350, will it run crapping?

 

The 88s had a 350 option, you just need to use the corresponding chip to the combo your running. The ecm isn't keyed to engine displacement.

 

Some things to keep in mind:

the 88 TPI setup is a MAF setup (165 ECM)
the speedo guage in a 88 is cable driven
the 90-92 TPI setup is a Speed Density setup (730 ECM)
the speedo guage uses VSS (electronic).

I would say use the 730 ECM in the 90-92 LB9 car, convert your 88 MAF TPI setup to Speed Density (slap the LB9 TPI on the L98 motor, then swap the 22# injectors from the MAF TPI setup into the originally LB9 Speed Density setup), and then put a Speed Density L98 chip in the 730 ECM. This would allow you to keep using the stock 90-92 speedo guage that uses VSS.

Sorry to say but you might have to make a custom chip (or pay someone to do it) as the L98's never came with the T5. Not sure exactly what it would affect (auto chip in a manual car), but I think the change is pretty easy, like 1 maybe 2 fields. I say just try the auto chip and if the speedo acts up then research the custom chip. Dont try to use the chip from the 305 on the 350 because the 305 uses 19# injectors and the 350 uses 22# injectors. It might run, but nowhere near a good tune. Good luck!!

 

Arrgh, I mistook what your were saying.

Temporarily you can is the 305 chip with the 350 since the difference in injectors is closely offset by the large injectors.

Long term you'd want to get the right chip.