66shortwide, ZooKeeper is correct, you will need to remove the manual transmission cross-member and install one from an automatic.
I pulled one from a 71 or 72 (can't remember which) that I found at the boneyard from a truck using a automatic. I got lucky and found one that was bolted in verses riveted.
First bolt the transmission to the cross-member to determine where it will attach to the frame (keep everything square) and attach the cross-member to the frame. I had to use my welder to fill in the holes on the new cross-member. Then drill where necessary. Of course the engine needs to be bolted in for all of this.
You will also need to shorten the drive shaft.
In the end it is a great combo.
