got a quick question. so i found a 350. its a 93 GMC C1500 5.7L 350 TBI. i currently have a 305 tbi. the guy said alls i wood need to do is put a 350 chip in my 305 ecm but that dosnt sound right. i was just wondering if anybody had any suggestions, thanx

 

do some searching, but yeah, the ecm is the same. Prom changes.

 

The chip is not a direct replacement from truck to car as the ECMs ARE DIFFERENT. That year truck will have a 8192 baud rate PCM in it with a Memcal like a TPI car. Get an ECM from a 1987-1992 Chevy/GMC fullsize Van, Truck, or Suburban with a 350. Get the ECM from a similarly equiped vehicle. By that I mean if yours is Automatic, you need the ECM from an automatic and vice versa.

 

this is what im trying to say. can i just put a PROM for a 350 in my 305 ecm?

 

NO

The only prom that would be better than a truck prom comes from a 350 police car. The civie L05 caprice was a gutless slug with the L03 peanut cam in it where the 9C1 had a stock L98 cam (works well with a LT1 roller cam in a 350 TBI, 68# injectors, an intake, and a performance exhaust)

 

Not to hijack or anything, but how can I tell which one I have?