Go with a solid roller cam, 600 inch lift is still streetable but not good for daily driving. i know people who have run 700 inch lift cams in big blocks on the street on pump gas. If you change to a solid roller setup that may require you to go with a longer valve then whats most likely in that head.

If your still confused, go to summit racing, open up to the cam page, close your eyes and point at the page and say i want that one, it might work hehe.