Good luck with that - those are getting to be pretty darn rare. I don't think you are going to find anyone around here with one to sell. You might want to have him check out Hemming's Motor News. I'm sure he could get one from somebody listed in there. Expect to pay a pretty penny. Unless he is doing a correct restoration, I would suggest putting a T56 6 speed in it. Awesome gearing and overdrive plus the benefits of a hydraulic clutch - they work really well in the early Mustangs and Camaros. I know they are close to being a bolt in in the first gen Camaros (aside from a bracket fabrication for the clutch master cylinder and relocating the console to accomodate the shifter. I don't imagine it would be more involved for an early Musting.