I almost went aluminum, it turns out a Fox body Mustang with a TKO swap uses a 45.5” driveshaft so that size is readily available. Only thing is they’re all 1330 joints. I reminded myself I already had a 1350 yoke and my car is a street car, so plain steel is just fine. I did go 3.5”, did a little looking and now I know it will fit if I ever decide to go aluminum.