If you are building a period-correct hot rod with an early Ford 3-Speed and a closed driveshaft, you will probably need to shorten the driveshaft. This driveshaft is designed to be used with 6-spline transmissions and rear axles.
The transmission spline is already installed, you just cut the driveshaft tube to length and weld the rear axle spline coupler in place. Tube length is 60° less the splines. Welding should be done by a qualified welder.