The motor, 700r4, and driveshaft fit extremely well.
I have heard quite a bit about the driveshaft having to be shortened when swapping out the factory 3 speed for a 700r4.
The 700r4 that I am using came out of a 1982 Olds 88 and the splines on the 69's driveshaft matched up perfectly. The more incredible thing is that the after mounting the carrier bearing in the exact same place it was originally, the dirt-line (no better words for it) on the yoke was in the same place when it slid into the transmission.
So, how is this possible? The previous owner swapped the original straight-6 for a 350 and used the original straight-6 engine perches with the v8 motor mounts. The perches are in the same back two holes on the frame where they installed in the factory.
Here is a picture before the body was removed and shows that there is plenty of room between the engine and the firewall. The headers even clear with lots of room to spare.
Did I discover something that the hot-rodders haven't shared with us?