We did a 530 for guy with those heads and what a pain in the ass.. Need special vavle covers, Jesel rocker shaft sys, special intake(raised runner),18* pistons,lifters were a trick. I ended up using big chief offsets for that. IMO, if you are looking for a NEW set of heads call Curtis Boggs!! I don't think those heads are worth it in a truck pulling appl. Theres better if you have to stay with conv. heads. go with spread ports if allowed
