The fellas are right about pulling the head and doing a little block prep before dropping the piston back in. If you find too many problems with your motor consider picking up a good used 261 to drop in. I've seen several available on stovebolt and the guys here are great about pointing you in the right direction.
I've got a '57 similar to yours and I've used it alot without any problems. Its great to pull a heavy load and feel the truck muscle its way down the road.
Would love to see some pics of your truck!!!
JAMES
