The engine is going to run a little rich, by definition. Who knows if it will run rich enough to carbon foul plugs…but a little hotter plug (R45) might be cheap insurance in that regard.

As for the RockAuto confusion, I ran it for a 1962 235 (my engine). It recommends the R45. For all other years of truck 235, RockAuto lists the R43. Weird. I don’t think it means anything, just an oddity in the parts listings.


1951 3100