I was looking at a rocker arm setup that resembles a Jessel setup for a sbc. This setup runs on milled down pedastals, has a bolt on base and runs 2 rockers per 1 shaft. Im told these are T&D's for GN-1's. Does anybody have any experiance w/ these good or bad ?? Im looking at these for a stock block, billit cam, gn-1 headed motor.