You're going to find a very wide range of driveshaft lengths in T-buckets. Wheelbase is one of the big variables in Ts. I know of a T that had NO driveshaft... just a U-joint between the tranny and the diff! This was a very short wheelbase car and the rear axle was hard-mounted to the frame. The shortest T driveshaft I have seen was about 9", and the longest probably around 3 feet. I have a short-tail TH350 and a Jag rear-end in my T, and my driveshaft is 18.5". My wheelbase 105".