Borg Warner upgrades

[Hot Rod]

Street driving -- approx 325 HP. Reading some other info on the net seems to relate one piece tail shafts need to be larger diameter tube. Apparently because of Commodore using 2 piece shaft can get away with smaller diameter tube eg. less flex.
The 1 piece shaft I mocked up seems to be a bit light on. Will a T400 yoke fit the T700 splines ?

 

[EYY]

T400 spline is different afaik