Swapping out for mustang parts
 

so ive been working on my truck, f150 flare side 5.0. Replaced all the basics. Spark plugs, distributer, wires, cleaned the throttle body ect. ive bought cold air intake, cobra intake upper and lower, fuel rail with regulator. high performance injectors, and headers. next is cam, lifters ect. i have only installed the cold air intake. ive been looking around for gt40 heads and im just hoping this all fits. this is my first project car, im not a mechanic but still pretty mechanical. im struggling with buying the correct cam. flat tipped camshaft? rollers? springs, seats? Ive done my best research and in theory it should all come together. any advice? i could really use some advice because everyone who i know thats a "car guy" seems to be not such a "car guy" after all. Any advice/opinions would be greatly appreciated!