The trans in my '62 F100 w/223 I6 is getting pretty noisy so rather than rebuild I'd like to upgrade to a '63 or later with the syncro 1st gear. My main concern is not having to change the bellhousing and retain the 3 on the tree. Clutch, pressure plate, throwout bearing and u-joints will be replaced while the trans is out. It would be nice if a later model drive shaft would slip into place so at to not have to modify the length of the old one.