Has anyone been following the updates of the aluminum heads they sure look promising ,latest dyno testing on them with a SS M-90 L-36 block with a 2.7" pulley at 13psi gave a dyno result of 425whp and 452whp with the convertor locked ,so it seems the head improvments they've made are excellent ,pretty pricey but you want to play you gotto pay .Chico(pops)