Will 8-3/4 alxes fit in the old 65 7-1/4 rear?

The weak link in the 7 1/4 is the chunk. My dad blew 3 in his 65 before going with the 8 3/4. I am not taking the chance and will be going 8 3/4 before It goes back on the road. Save yourself a headache and put the whole thing in.