I am going through my 91 350 and want a bigger cam. It has Sportsman II 220cfm heads, 1.44 dual springs, 2.02 1.6 valves, performer RPM intake, 670 truck avenger, corvette manifolds, dual 2.25 exhaust, auto, don't know about the converter, 4.56 gears in one tons and 37" SSR's. Right now it has whatever comes stock in a 91 cop car for a cam. I was thinking about the factory ZZ4 cam, it's right at .500 lift but I would need 1.6 rockers to get the lift I am looking for. Am I crazy for wanting .550 lift in a truck?