If its the old rail style rockers you can go over.500 lift. just grind the rails down on the rockers a little so they dont contact the retainer. the press in studs should be ok as long as the spring pressure is not too much, or we used to pin them. the cam you asked about is a little much without a converter. I would keep it around .480 and a little less duration especially if the car is heavy and has highway gears. how much does it weigh. and what gear ratio in the rear ?