66 valiant 170

I love mine. Although I'm gettin ready for the 225 swap, I'm keeping all of the original drive train. If there's something I don't like about the 225, 170's goin back in. lol
I’m having a hard time finding a rebuild kit for mine. Think I should do the 225 swap? Seems like rebuild kits are pretty plentiful with those. If I can 64-66 that would be ideal but outside of oil pan, pick up, mounts, flywheel anything else I should consider? Oh and head pipe for exhaust.