so...at the junkyard today, my dad and i ran across a 91 or 92 RS, 305 TBI (i guess, i dont know if maybe someone had swapped it out for a 350 or not). layine in the passenger seat was a shiney, new-looking ecm, and when i got to looking, there was no ecm plugged into the car's wiring harness up under the dash. i new it was a different ecm than the one in my car (91 305 tbi), but i didnt know if it was for that car or not. we went ahead and bought it anyways, and when we got home we pulled the little cover off of it, and noticed that the chip looks almost identical to those found in computers for a TPI car. however, when we took the blue cover off it it to reveal the eprom, there is an extra, i guess you could say larger chip plugged in over top of part of the eprom and the two smaller chips beside it. i've done quite a few searches for the 16197427 ecm, but i havent really found the kind of info i'm looking for.
-the question im looking to have answered, is if i were to program a chip for it, if it would be a better ecm to use than the stock on in my car. what i've read so far about the ecm kind of confused me because im still a litle new to programming.

--my car is also a 5-spd, so i was also wondering if the ecm would still be compatible, because i've read a lot about how they were designed mostly for the 4l60/80 transmissions.

any light shed on this subject would be greatly appreciated.

thank you,
-mike

this ECM was used on 94-95 Trucks and Vans and of course, has a memcal instead of only a EPROM

and you're right, in fact it's a PCM because it's designed to control a transmission too.

maybe there would be a way to use it in your car, but not without changes in the wiring harnes and chip - so keep your existing ECM

This PCM was also used on the 4.3 5 speed trucks.