do a search in this forum and the engine performance forum and you will find TONS of reading material. ignition, exhaust, heads, cam, efi setups, transmissions. on and on

you will have more options for heads with a carb setup. youre obviously not restricted by emissions issues so long tubes and a free flow exhaust are no sweat.

personally, i love the efi even with the speed density setup. with a maf setup from a later truck or a mustang you can do whatever you want for horsepower and not have any fueling issues. my $.02? stick with the efi and enjoy the reliability (assuming proper maintenance)

if you dont mind some fab work and tweeking, the zf transmission is the s$%t. itll be some work to switch but its a great transmission. the overdrive is great to have. a c-6 is a solid auto but i did read somewhere (fte probably) that it uses like 67 hp. and, of course, no overdrive.

have fun dude. put up some pics!