Ford Motorsports makes a whole grip of performance parts for 5L engines. Go to your local Ford dealer and grab a catalog.
Aftermarket manufacturers who seem to specialize in Ford performance off the top of my head:
TrickFlow Specialties(TFS): cylinder heads
Air Flow Research(AFR): cylinder heads
Comp Cams: camshafts
Edelbrock: intake manifolds, cylinder heads and anything else you can think of
Borla: exhaust
What you really need to do is join some Ford performance clubs online, pick up some magazines and get as many catalogs as you can and read, read, read! The 302 is almost as common as the sbC and is fairly easy to wrench on and parts are easy to come by. Like everyone else has said, the main areas to concentrate on are the cam, heads, intake and exhaust- remember your engine is nothing more than an air pump aided by combustion. Ask questions, do your homework and make the right decisions. Good luck with your hop-up.
I'm a diehard GM/sbC guy and I can't believe I just offered help to a Ford newb. I need to go take a shower now- I feel...dirty.
