A bone stock 360 in an A-body with a TQ carb & intake and heads w/2.02" intake valves will go 13's all day long if it's got a little gear & traction. How much will it take for a Slanty to do it? It was small intake valves & cams that hurt the most, even tho' the low squeeze certainly hurts them plenty. Slantys don't do any better in the stock squeeze dept. even with the flat-tops.