That was the issue thanks guys

Been trying to build the 390 for my 68 cougar for a while now and keep running into problems with the rear most main bearing with the thrust surface. It doesnt seem to matter what bearing set I buy, none of them will fit over the journal. So far I've tried clevite part numbers ms683p and ms685p and q sealed power that I cannot remember the part #, and they are too narrow to go over the journal in the block and seat. They will fit on the cap without any issue (a little snug, but pressed on by hand. Anyone ever come across this? Any suggestions?

I do have access to a set of c8ae-h heads. I could pick them up for reasonable price and have those worked instead. If I buy those heads, they come with the headers....so I guess I could see if I could make those headers work

On that note, I'm open to suggestions for what headers will work for anything resembling a reasonable price.

I unfortunately have no clue.

I have run across a set of headers for a 68 ranchero, which i believe was a fairlane body with a 390, I am wondering if they will fit in a 68 cougar, or if they can be made to for without too much issue.

Thanks for the replies, I've decided after a lot of thinking and reading that I'm going to keep it a 390 in the interest of keeping costs down to pay for other goodies down the line a little.