Our 54 came with R45's in it and the box of parts that was with it had R 43's in it so they got put in after I read they were meant more for highway driving as opposed to in town driving (different heat range) Not sure if that made any difference. I had trouble starting the truck this year so it now has rj8c champions in it as that was the only plug reference at out local parts supply.I think most of the problem was my points though.One of the guys at our auto parts place in an old chevy car guy and he knows his stuff which makes quite a difference.
