trans choices

About time to get serious about a tranny, In a Street Machine/Pro Street/Drag Car frame of mind. Any reason to choose either a long or short shaft T400 over the other style? A buddy has a good T400 short tail shaft for $100 out of the car. Another bud offered me a good long tail shaft truck T400 for free ,pulled and delivered. Givin both are in good usable shape,(I drove both), Which is the better choice cost aside? I am committed to a T350 or a T400 as the car is setup for a 3 speed w a B&M ProRatchet shifter and both t350 and t400 style mounts. This Xdrag 10.50's car 3500# 72 Nova is going to be used mostly on the street w a 450 to 500 HP max BBC and only a few drag strip runs a year.

If you already have the drive shaft for the car, it is probably going to fit the short tail with no modification to the drive shaft. I would go for the short tail, less tail shaft length means less chance to twist it up.

Driveshaft is set up for a T350/PG now. So driveshft work is coming anyway, but I'll probably just have another made so the car is still T350 or PG setup for the future. Was just curious as a local trans ad claimed that the long shaft T400 tranny was better due to less Ddshaft rotating mass ??? sounded like sellers gimmick top me so I asked.