ahh there is a place here in aus that makes custom bellhousing's for the t50 onto the a12 have a look for dellow automotive
you can get datsun 5 speeds but they cost a fair bit here in aus in the usa they sell fairly cheap
the sereis is
56a dogleg and maybe normal shift?? used behind the 1200 and a12
60a and 60L used behind the a15 a14 datsun sunnys? dogleg and normal shift the latter being the dogleg
and 63a is used behind the a15 in im not to sure what car but it is dogleg
normal shift pattern is
1-3-5
2-4-R
dogleg is
R-2-4
1-3-5