Ok everyone! I know this has been beat to a pulp. But currently what oil preferably conventional is good enough to run in a 360 with stock clearances? I have been using 30 weight vr-1. But need other sources of oil please!!:)
There are a lot of good replies here already but I'll put in my 2ยข.
While flat-tappet engines require ZDDP, those with oem-style valve trains don't need huge amounts. The thickness of the ZDDP layer doesn't depend on ZDDP concentration. Since the layer is sacrificial, more ZDDP really just extends how long you can run the oil. Engines with high valve lifts and spring pressures consume ZDDP additives at a faster rate than milder engines. See Engine Oil Myths - GM TechLink and Engine Wear.
For valve train protection, Heavy Duty Engine Oils are better than racing oils because they also have high ZDDP levels but have better detergents and will keep an engine cleaner for longer. See the Corvair Oil Guide. 30-grade oils that are approved for API CK-4/SN are considered resource-conserving and are limited to 800 ppm of phosphorus but 40-grade HDEOs (like 15W-40) are limited to 1200 PPM even when approved for API SN. Phosphorus is the antiwear component of ZDDP.
I run semi-synthetic PetroCanada SHP 10W-30 in my car because it uses the SHP 15W-40 additive package so it has the high ZDDP level of a API CK-4 oil and meets the 1000+ PPM requirement of Ford WSS-M2C171-F1 but is good for gasoline engines because it is suitable for API SN.