Motor Swap

I'm assuming it was cracked when I bought it? Haven't done anything that would have caused it since I've had it. I know it got super hot on a 6 hour trip in 95 degree weather last August and we couldn't figure out why.

Not sure if the motor is original but it is date code correct.

C: 1967 model year
225: Engine displacement
3 07: Engine built on 7 March 1967
Iron cross (called a Maltese cross) followed by X: All rod and/or main bearings 0.010" undersize when engine was built.