Welcome to the forum!
First things first, get that crossover replaced, that will cause all kinds of running issues with it. Exhaust leaks wreck how these cars run.
A point of advise, probably not relevant at the moment but I seem to remember decreasing the spark plug gap from whatever the factory recommends to help with some other running issues.
There is only one person i'm aware of who repairs those at this point. Forum member GOT2BGM aka Matt Shantz he's not on the forum much these days I'm sure he's active on the various facebook w body groups but regardless i'll shoot him a message to drop by the forum.