Rear end gearing tech question

Depends on your tastes. I want the engine's cruise rpm at 55mph to be at or above the stall speed of the convertor if it's a street car. With OD and a 2400rpm stall you'll need more gear I think. If it were me I'd consider dropping the stall speed. IMO you don't need that much with a 360 in an often-driven street A body with a blower. A lot of guy with N/A might need it, but you won't. And crusing in OD below the stall speed will create a bit of heat in the trans.