Hi guys, I swapped the 4L60E in my LT1 wagon for a T56 and everything works great except that the starter grinds for a second or two after the car starts. I used a spec billet flywheel...when starting it doesnt make any abnormal noises but once started its like the starter isnt disengauging fast enough as if i was turning the key after the car has already started.

I've tried the following:

loosening the starter and pushing the back of it as i tightened it to prevent preload forward - same result

I shimmed it 0.020 - same result
shimmed it to 0.040 - same result
shimmed it to 0.060 - same result except instead of a 2 second grind its a 0.5 second grind...pause....0.5 second grind
shimmed to 0.090 - starting sounded wierd and once it started it did the grind pause grind again...

I dunno what to try next, my flywheel teeth look perfect still...thankfully ...so did the starter gear.

Any ideas or has anyone else experienced this going from flexplate to flywheel? thanks