ok i have an 85' 305 TPI Z28. i also have the ecm from my old car... my 89' formula 350. i have been thinking about installing the computer from the 89' as the computer from the 85' sucks. i will need to burn a new chip because the 89' ecm is from a 350, if i was going to use a stock prom set, what year 305 would yeild the best results? by the time i do this i will have done some slight mods.

 

also... will i feel any performance gains from the ecm switch?

 

For this, you'll need to modify the wiring harness some. Go here:

http://www.eecis.udel.edu/~davis/z28/ecm_swap/

for the best documentation on this swap. You can look in the GMECM bin library (see posts from yesterday) for the APYM if you have an automatic. Mike has the '89 305 M5 bin on his website if you need that one. For best results, get the ARAP bin, change the necessary parameters for your 305 (injector constant, idle speed, lower the timing table some, etc.) and have fun. AFA your other question, you'll pick up performance by burning your own chip more so than going with the '89 ECM.

 

Geez boyz and girlz, can't we just say that later ecms offer more flexibility - you're hurting my feelings