SLIP JOINT...That's the part name I was looking for.

In a full size pick-up the u-joint at the transmission is bolted to the output shaft. The slip joint is at the center carrier. the u-joint at the differential is bolted in.

Since it's about 52" from trans u-joint to diff u-joint, why bother with a center carrier. I'd like to use a slip joint at the trans, and a one piece driveshaft, like in a car.

Can I use a slip joint on an output shaft that is only 4" long?

Since I can't find a TH400 with a 9" or 12" output shaft, should I opt for a TH350 with a longer shaft?