i have a 84 z28 w/ 355.right now i got a set of 993 heads on it.194 intake 154 exhaust 76cc chamber ported and poished. cam is a comp exstem 268/280dur 477/480 lift, rpm air gap intake, 650 double pumper, msd ign. i was thinking about putting a set of 305 heads on it. they are the 416 cast,intake is drilled out to a 194 /150 exhaust ,shaved .10 ,and have a 58 or a 62cc chamber.would this help me or hurt me. the car is not driven but on the weekends, some track use.