Boltergeist and Shop Shark...
I forgot to mention that I'll be installing an aftermarket Mustang II so previously mentioned issues hopefully I won't encounter. I have read about moving the bellhousing crossmember back to accommodate the tail shaft of the transmission and modifying the "back" crossmember to accept the driveshaft and any additional clearance issues. I understand that removing any support parts from the frame is a bad idea. I have boxed the rear of the frame from the back of the back crossmember to the support that is riveted in just past the axle hump of the frame. My main concern was torque issues on the leaf springs. As we all have grown accustomed to, we leave stop signs and such with a little more "umph" than we did 70 years ago...horsepower being the culprit. I was just concerned that the 1 3/4" wide leaf springs would hold up for how I expect to drive.