i recently purchased my 87 iroc...the car was originally a 305 TPI..and the previous owner swapped in a 350 TPI from what he said was a 92 camaro...

im having a low idling issue...that i believe is from the PROM being for the 305 and not the 350...(this is a mechanic told me and im looking for help to confirm this is the source of the problem)...i was told to purchase a PROM for an 87 350 motor and that should solve all my low idling issues...when driving the car is fine, right up where it should be around 13-14 volts...when im slowed or stopped the car will dip all the way to 11.4-12.2 (have a digital gauge)..can anyone confirm this is solve my problem? if not...what would, any help is appreciated!

 

i wonder if he put 350 injectors in it i had underdrive pulleys on my car and when i would stop the volts would drop