The only time I was able to run that small of a pulley knock free, was when I had 1.9 rockers wizaired, headers, stage 3 IC, 180* tstat, hogan DP with hiflo cat, Lightning injectors, fp rewire, allt rewire, stage 1 vboost, and a custom tune. I was still on the edge of knocking, but those were the mods I had when running a 3.0 pulley.