dude, dont waste your time with that little cam on those kind of heads. if i were you, go with this combo, its tried anf proven to work, and will net you at least 325+ rwhp out of a 302/306.
1) afr 165cc heads
2) holley systemax II intake
3) CROWER 15512 CAM!!!
more than a couple of friends run that combo, and are in the mid 12's on motor and all over 330rwhp with supporting componenets. one of them runs that combo carbed, except with a fully ported edelbrock performer rpm gap intake, a holley 750carb, and a electric pump.. and made 368rwhp/360rwtq on the motor and ran a 11.94 @ 114 in a 2900 lb coupe. telling you, that combo is the way to go.