Later engines and GMC's are longer, require rad relocation far as I know! Only 54 had correct waterpump length and location to drop in. You can use your orig bellhousing to match your frame x-over and mounts are same in front. You can convert your babbits to inserts, have to find right suppliers, and it is costly.
www.chevsofthe40s.com does that work, and think Carter's does, and look into the
www.inliners.org site for more changing info. If yours is not smoking and has fair compression, just do a tune-up and run it! Just a valve job may help, but may pull more oil then w/out more rebuilding.
