Quote: Probably because he is using the wrong plugs , that looks a later 452 , Police/motorhome head and it takes the 5/8" hex tapered seat plug , I used an AR24 autolite.
huh? I've had many sets of 452 heads and none had this goofy nub that prevented me from using normal spark plugs. And they all had the casting number 452 on them. Does anybody know what is the significance of this casting number?
