@Mopar Tim OK, excuse my ignorance, but you can't pull the GV off with everything in the car? Is it due to the modifications you had to do to the car doesn't allow it, or what is the issue? If an upper fastener, I personally would find a way to get at it before pulling the whole drivetrain out. Also, it doesn't allow removing the transmission and GV? or is that due to the routing of the exhaust? If exhaust, then I would consider cutting pipes and using the band clamps at reassembly. Things need to be able to be taken apart or removed without removing the entire drivetrain. No offense, but issues later can be helped/solved sooner than later.
Hell, I would use a hole saw to have access to that hole and use a body plug to fill it when done.
Hell, I would use a hole saw to have access to that hole and use a body plug to fill it when done.