I received the ATI flex plate and had the same issue. Called the Torque converter company and their answer was to drill the flex plate holes slightly larger... called ATI and their answer was drill the flex plate holes a little larger.. Sooooooooo, 1/32" was all it took. Drilled each hole equally on a drill press in 1/64th increments keeping everything in alignment. The holes were exactly 29/64" and ended up 31/64"
Made a little progress, hopefully back in the chassis this weekend.

Found some ambition last night and got it back in

Looks awesome and now I am going out in the garage because of your post.

Slowly chipping away at it..
Got the Derale trans cooler in and lines made

Got enough hooked up to hit the key and make it come alive again

It's been a little while and just messing with it little at a time. Pulled the engine and trans again to get better access to the firewall and trans tunnel.
used a lot of elbow grease and mothers aluminum polish and tried for a mirror finish then coated with Sharkhide.

Swapped out the junk Koni's for some QA1 double adjustables

Finished the front wiring harness and added Second Skin Megablock insulation to the trans tunnel

Put the engine and trans back in, cut and welded flanges on the new Borlas then wrapped them with DEI Form-a-shield to hopefully reduce the amount of heat coming up through the floors.

Added a small panel to hold a bus bar, vintage air relays and circuit breaker. Bus bar gave me a great place to connect the vintage air and the Micro steering. Plus a stud for common ground.