If your 235 has a fiber camshaft gear and you are replacing it with a fiber gear, I doubt that there is enough wear on the crank gear to warrant replacing it. If you have a aluminum camshaft gear or are replacing a fiber gear with a aluminum gear, I would replace both gears. And yes the crank gear can be replaced without removing the crank.
Cleon


Life is like a roll of toilet paper, the nearer the end the faster it goes.




1949 Chevy 6400
1931 Chevy Firetruck