Just purchased 99 Maggie SC C5 with many "supposed" upgrades. long story short is that I was misled.
Car was supposed to have z06 rear with 3:42 but...
Got to be something I am over looking for the Idle setup once in gear or AC comes on to add more air from the IAC, its bound to still be operating on...
Thanks for posting. I'm interested to see what you worked out vs. what I've got. I'm in the same boat, project got put on hold so I haven't had much...