66 valiant 170

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.
I prefer the 170 over the 225. When the 225 in my wagon finally bit the dust at 300+ thousand miles I put in a really sweet low mileage 170 and also pulled out the tired automatic and put a 4 speed from a 65 Barracuda behind it.It's way more fun to drive now and gets great gas mileage when I travel.