If wanting to go "OD", TH200-4R (NOT to be confused with TH200, a completely different "animal", and major POS) is superior to 700. The trans guys I know say to use that one, with an upgraded sun gear and shell, and it will out-perform and out-live 700 behind an engine with low-end torque. 700 was designed for small block and V6 Chevys. 200-4R will literally bolt right up to the 326. 700 will require an adapter.
RoadRageDavid's '68 Firebird ran a "Level 10" 200-4R for threee years without issues, 500-plus HP, close to 600 lbs. of torque, clocked at least once at 200 MPH.
Either will deliver the OD you're looking for. Chevy guys "like" 700 better for obvious reasons. That's why there's so much more "info" out there about it.