Are there more than one style of short cast iron headers and how much shoud they sell for? Also whats the going price for a complete 3/2 carb setup with intake go for? and air cleaner cover?

a number of factory headers were cast for the big block fords in that era , at a swap meet expect to pay 50 to 75 for those, but the 3 duce ford unit will set you back about 300 in fair condition without the filters

You better convert to Disc brakes too.if you build it and it goes as you hope it will. You are looking at almost 200 feet to stop at 60mph with it stock.