Sep 10, 2007 #1 jefflock 69 Dart 408 10.08 best pass so far FABO Gold Member Joined May 18, 2006 Messages 3,515 Reaction score 113 Location Kansas What are the differences between J heads and U heads? Thanks Jeff
Sep 10, 2007 #2 3 340mopar Sorgermotorsports Joined Jan 25, 2006 Messages 3,604 Reaction score 17 Location Soap Lake, WA If they are "915" castings, nothing. Chuck
