Lucas Response To Zinc Additive

I bought my 74 Gold Duster with a stock 318 2barrell back in 2001. It had a terrible miss. It turned out 2 lobes were wiped out. Only car I have had that had that kinda of damage. Who knows what oil they put in it before I got it, probably Wal*marts finest? I bought it from a guy in a trailer park(not a nice one). Back in 2001 I was using Mobil 1 and never thought about zinc and cams. Lately I use Valvoline Racing. If you use Valvoline racing oil, get the not street legal in the gray bottle, not VR1 which is for modern engines. My local NAPA had the gray bottle stuff but Autozone and Advance did not.