Hi, Is the 1965 mustang 200 ci engine rated at 120 hp, and the 1979 200 ci engine (which they state is rated @ 89 hp) still the same engine as far as horsepower produced? If they are, would I have any complications when replacing the '65 engine with the '79 engine. Would they hook up with the same electrical connections? Any thing else I would need to know? THANK YOU!