:agree: yes, it's an excellent site keith. there's alot of good info on zddp, or lack of, in modern engine oils. crucial for flat lifter camshafts. many engines are wiping cam lobes because of inadequate zddp content. i use delco e.o.s [engine oil supplement] one 16oz bottle to 5lt. it won't be an issue for me though when i build the 406 because i will use a roller cam.