What determines whether the ECM is for an automatic, or a standard tranny? The PROM? Or the CalPack?
The reason why I ask is because when I look up an ECM for a 90 Chevy Pickup for a 350 TBI application, it gives the same part #1227747 for ALL applications, thus leading me to believe that the PROM that is installed makes this determination.
I have the 7747 in my car now. It is from a 305 TBI truck with auto tranny. I need one for the 350 TBI, with manual tranny.

Does anyone know this info for SURE?

Thanks,
SLC

 

The prom is the difference. The ECM is just the hardware in this case.

You want a prom from a manual trans application. For sure.

 

Yeah, having an auto PROM in a manual prsents some funky problems, like when coasting to a stop, it dies when you step on the clutch, and other weird stuff!

 

In the world of ecms the 747 is very basic.
The calpac (netres) sets some basic engine function stuff and limp home mode fueling. For the 747 it's not that critical, HOWEVER in some other ecms it does matter.

You always want to start with the prom and calpac that most closely resembles what your working on.