Engine in car tomorrow---------

My GV fit into the tunnel, behind my 360/A833 with just some minor massaging of the 68 Barracuda floorpan. I used a PST poly rear mount on a 73 X-member, and factory front biscuits, with a Schumacher strap.I did slot the tranny mount down;maybe about 3/8 inch.
Sorry to see you had to drop the tail so far.

My TTIs and dual 3inch exhaust runs pretty tight to the floor, cuz the engine is raised a bit, but probably, it would still clear that drop.