The input shaft has a different spline count so either a special convertor or change out the input shaft to the 67 & later piece... I agree the B&T will take some abuse but parts are hard to find & once the assembly wears it won't slip in & out smoothly... I'd build a 65 trans which is still cable shifted but uses a slip yoke & I'd use the 67 & later style input shaft...
BTW Nice 64!
"The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."
