90 Turbo 400 to 94 4L80E swap

So I’m doing a th400 to 4L80E swap on my 1990 gmc tbi 454, and was looking for some answers or help on the swap, I already have the transmission, a rebuilt kit (since reverse and OD blew) I got a atomic independent trans controller from Holley and a wiring harness for the controller since my year didn’t have the electronics for it. Does anyone know if a stock 04 torque converter from the big block or duramax would work and bolt to the flex plate? If not does anyone know a flex plate that would bolt to the crank bolts assuming they changed them? Also does anyone know if there is a huge change in shift linkage or if it even matters (I was going to change the PRND12 in my truck to match a truck with OD. And last thing are there any changes to the tranny mounts, clearance and how much the driveline would need to be shortened? Thank you