will a Slant 6 hurst four speed from my 64 work behind a 360

If your four speed is indeed an A833, you need to establish the front bearing retainer bore and choose a small block bellhousing or scatter bell with that bore. As stated above, stock 360s and cast crank 340s use the dampner and flywheel (externally balanced) to balance them, so a flywheel specific to your engine is necessary. As stated on other posts here, the slant six torque shaft will work but need to be narrowed one inch. The slant six throwout arm and throwout bearing will work. Rear crossmember, rear mount, and shift linkage stay the same.

Slant six 833s are the same internally as any other common 23 spline 833 and hold up just as long as one originally installed behind a small block. Bear in mind, during the design life the factory made running changes that improved or made it cheaper to manufacture (shift interlock and syncros come to mind). If you are concerned about the age and wear of your particular transmission, or just interested in upgrading the strength, contacting one of the specialists (Passon, Brewers, others?) is probably your answer.

The OD 833s are not as strong due to factory design changes to make it overdrive, but are reputed to stand up fine under normal use (the unbushed aluminum case ones aside). If you have the money and strength in an issue, Passon Performance has gearsets, cases, or complete transmissions that address the strength issues of the OD.