7 1/4?
I busted a 7-1/4" in a slant six Volare. There was a hole where something exited the rear cover.
I went to the work to replace the rear axle only to find out that the trans was now junk. It would be ok in first, then shift to second and make some nasty noises and shake the whole car. Apparently, the trans didn't like the shock load caused by the rear end's failure.
Needless to say, I'm not a fan of the 7-1/4. Have some patience, save your money, and get an 8-1/4. I would hate to see you with a busted 7-1/4 and a busted trans.
Oh yeah... it's possible that you'll need to mess with driveshaft length - watch out for that extra cost.