I would also add...without knowing the condition of your car...what about cooling system? Larger radiator and new fan? You noted wanting a new trans....have you thought about just adding a seperate trans-cooler?
I have a 302 in my 64 1/2 convertible and the best mod I did to it was put in a 4R70W transmission with a Baumann electronic controller. Other things I did to the engine is AFR 165 heads, E303 Ford Racing cam, JBA shortie headers, Flowmaster exhaust, Edelbrock RPM manifold, and Edelbrock 4 barrel carb. I also replaced the stock rear end with a 3.55 limited slip. This car sounds and runs like a dream.