Quote Originally Posted by 1project2many View Post
Well, you've just arrived at the heart of the issue. The 165 was "good enough" even though vehicles with a more recent design were getting a better ecm. OEM choices are based on economy and profit. That's what business is. But you're in a different space.

Think of it this way... the 5.7 / 350 was "good enough" until the LS engine was introduced. But you're using a 383 instead. Why? And if you're using a better version of the factory engine what is stopping you from using a better version of the factory ecm? The 7427 has more features and more tunable tables. The LS pcm has more tables and features than the 7427 and it has a faster processor.

If you want to run dual pcm's, follow the instructions in the pdf previously posted.
The 165' was also only used for about 3-4 years. 85 had a 1 year only ECM with a seperate maf burn off aka "burnout" module as I like to call it for its ability to commonly fail which then killed the MAFs by baking the sensing wires during a prolonged burnoff session and then in 1990 GM moved on to the far superior speed density 7730 ECM and the underhood 7727 equivalent.