Dashh Dash you will need to find a cobra manufacturer that will change the motor supports in the frame for a BBC motor. Trans mount may need to be changed for length also. Wiring is wiring. Cooling system with a good 3-4 core radiator should control cooling. Does this motor have the correct rotation? You will need to check hood clearance with this motor depending on intake manifold and carb. This car is for you, if this is what you want in it, do it. There are not alot of cobras running motors other than FORD ones. Havr you thought about buying a cobra already done and using this motor to have a down payment?
That BBC is also a 700+ pound hunk of iron. 95% of the guys are trying to lighten the car, not have a boat anchor in the front end. Aluminum heads ,intakes, brakes calipers, drive shafts, blocks, and trannies cases, are all for saving weight. Your BBC motor is a good power unit, most guys just don't mix and match companies. What trans are you looking at? Which ever way you go, write up a plan and stay with it. Rick L.