Every car is different. A friend of mine has a 2000 bonnie with a high compression top swap and a fully ported gen3 blower (My old one, was a budget top swap) . His only supporting mods are gtp injectors, a tune, Plugs and a 180tstat. He has 0 KR and he is running a 3.6 pulley on 91. But then you also have the cars that have headers and can barely squeak by with a 3.8" pulley