1980 F100

I'm rebuilding my 300 straight six. It'll be built up n' down to handle 3 weber 450cfm carbs on a triple intake. About 390hp and 500ft.pds. of torque, and 11:1 compression. The stock tranny wont do. Any words of wisdom? What would you use?

thats a lot of horse pwer for a 300 where did you find the intake . as for a tranny put in a np245 darn near bullit proof what kind of rear end will you be using