I am doing my first motorcycle build. I bought a 1980 cb750k and after tearing the motor apart, its going to need a lot of work and money. the bike was left outside and had fallen on its side for who knows how long. I found a 1983 cb750 nighthawk motor for sale, which will be cheaper for me to buy than fixing the motor I have. So, will the 1983 cb750 knighthawk fit into a 1980 cb750k frame with or without modifications? any advise will be appreciated thanks