Ours is ya 432.... and Ihad read somewhere that it was in the range which had loose inserts. Now I can check the rockers and see what #'s they have. I bought a set on here {see much earlier post] c/w shafts and assembled but 3 of the rockers actually have crooked inserts on the valve stem contact end. Have not changed them yet, but still tapping about the same now as when we bought it.