So, its time to change oil in the 505 engine..... roller rockers and roller cam.... Zinc not a requirement I have read..... so like a Mobil 1 synthetic? Interested in what you guys are using in your roller engines ......... Muscle Motors in Michigan who built this engine back in 2012 seems to be no longer in business.... and the guy I bought it from and stored it for all these years can't remember what he used..... he thinks a straight weight 30w or 40w..... which I think is to thick for cold starts....... appreciate your input.... M