I read somewhere that 96-2001 Ecm was the same except for programing, any one know for sure.

 

not true

 

agreed... not at all the same.. only thing in common is they run on 12v negative ground and are in an Fbody.

 

94-97 are similar. The main difference is the OBD-I (94/95) vs. OBD-II (96/97) configuration, and they are not interchangeble. Starting in 1998 with the LS1 engines, the PCM is completely different, using a much more powerful, faster operating system, and significant differences in, for example the ignition system and the source of the crank and cam position data. There is no way (short of some major surgery) to put a 98+ PCM into a 94-97 with an LT1 engine.