From what I’ve read, all the small sixes have the cast intake with the head, but one could have the old intake milled off so the head could accept a...
I'd maybe try some 15W-40 or some 20W-50 and see what happens. If it's already that tired, probably ain't much gonna bring it back. Some folks around...
My Cars:
-1964 Comet 202 (116K Miles) - Awaiting Resurrection
-1987 Grand Marquis Colony Park LS (325K Miles) - April 2017 + September 2019 POTM Winner
-1997 Grand Marquis LS (222K Miles) - The Daily Workhorse & March 2015 + January 2019 POTM Winner