Hello. My friend gave me the body of a jackson JSX 94 and i have done some research on it and found it had a 22 fret neck. could I put a 24 fret neck on it or would it send the intonation right out?

Unless you can find a super freaky neck that would start in the same place and just extend the fret board over the guitar body, then it would upset the entire scale.
It wouldn't. Normally fretboards just extend over the guitar body. Your neck pickup might get in the way, though.