Your '92 should have come with a 16149396 ECM. That is a functional equivalent of the 1227727 ECM (weatherproof version of the 1227730) used in Corvettes and several other W bodies. It used a 256K UV EPROM for program ROM with a 2K backed S-RAM extension for electrically controlled transmission functions. The base engine parameters can be changed without even touching the transmission functions.

The label on the ECM outer case should indicate the service part number, as well as the stock broadcast code for the binary file used for that vehicle tune. The code should be in the format of four alphabetical characters, such as "APAB" or something similar. What code was originally installed?

from this thread:
http://www.automotiveforums.com/vbulletin/showthread.php?t=901856&page=2


my /94 3.4L v6 DOHC engine: Right now, its running on a replacement ECM taken from a /95 Monte Carlo (info was handpainted on casing), if the markings on that are any indication. It doesn't look like anyone burned a special eprom for it.