The '46 rear is the widest at 61" drum to drum, fenderless it might be ok. http://www.jalopyjournal.com/forum/showpost.php?p=8091493&postcount=12 The person who did the closed driveline T5 is crazydaddyo on here: http://www.jalopyjournal.com/forum/showthread.php?t=256226
My answer to anybody that is trying to make a decision over a new part or an old one is If it doesn't make any difference to you use the new part and sell the old part to someone who just won't build without it. If The new part goes you just just go to your local junk yard and get another one. If the old part goes you've wrecked something that is hard to find parts for and difficult to repair once you get them and you might just throw up your hands and let it rot and we've lost another old part.
speedway motors sells the conversion for the closed rear to a open rear that way you can adapt any transmission and drive shaft to your 1920's to 1948 rears
Ran a banjo in my rail behind shorty glide and small block chev for years had to put a bolt tentioner in the case for ring gear flex but hey it was right at 500 hp.