I bought the wrong transmission for my 66.

At this point, You have 2 different routes to take.

1. Fix the cobbled mess you have. Use the 5.125 bearing retainer on the A-Body A-833, get the trans tunnel where it should be for the A-Body shifter, and get the A-Body rods and arms. Get a new drive shaft or a used driveshaft from an A-Body Barracuda, Duster, or Valiant with a 904 and your rear. That should be easy to find.

2. Find a B or E body standard transmission, since you are using the front shifter mount, and use everything else you have.