are the 305TPI and 350TPI ecm interchangeable? Blackrob91 called advanced auto for a 350 ecm because he thinks his car still has the 305 ecm in it from when the guy before him swapped the motor to a 350! IF it does what problems would this cause? And how can we figur out if he has a 350 ecm or a 305?

 

ECM is the same as long as we're talking MAF to MAF or SD to SD.

MAF from '86-89 used the '165 and SD frmo '90-92 used the '730.

Chances are if he was able to plug in his harness into the ECM, he has the correct one.

The EPROMs/MEMCALs (chips) are different though.

 

how would he check his prom? would it be a better idea to just get a chip or something?

 

He'll need to pull it out and check the numbers on it, then search or post up, someone will probably have the answer as to wheter it's a 305 or 350 chip. If it's a GM chip, he can just call the dealer for info. If it's after market, he'll need to call the manufacturer.