rust bucket

I have an 84 pickup with a 22r. I found my no spark issue was due to the distributor being seized. the cam gear was totally chewed up and after some work I was able to remove the distributor (it got destroyed in the process). Upon cleaning the distributor and the head it appears that the distributor and the head had friction welded together, there is galling present on both the end of the distributor and the hole in the head that it goes into. There was plenty of oil present in the recess under the dist. gear and the timing cover bolt under the dist gear was tight as it should be. My question is what is a good way to hone the hole in the cylinder head so that i dont have the same problem when i install a new distributor and cam gear. has anyone else had this issue? Also many years ago I replaced the timing chain with a duplex chain, does this require a different cam gear? TIA