727 v8 to 7 1/4 drive shaft

You didn't state what wheel base/ car.
I wish you luck but I had to have a shaft made for that combo ( 67 B'cuda ). If my memory serves correct it was 49.5 from c <-> c of yokes. I sold it years ago. Buyer said it was correct for his needs to 8.75 rear. What I don't recall is his trans, 904 or 4 speed. Anyway... another more popular application explained why I couldn't find one available. Again, Good luck.