i would and have used the steel ATI.s why would you want to angle mill your heads ? you have alot of cr now for the street ? or do you want more ? i flat mill heads rolling the heads your going to get more cc off this way but your intake will need to be re cut your head bolt holes need to be re spot faced $$$ it realy not worth much as i see it less its the only way you can get the CR you want and its worth the $$$