Early LA 360 Blocks

I don't see why you would need a newer 360 block because you want it set up for a roller cam, maybe if you want a rollered stock engine other than that who cares. The op is talking about 400+ CI, the new Roller Lifters take the guess work out of the equation when going roller cam. The block I used for my latest build is a 1973 360, it passed sonic test no problem and I used Brians solid roller lifters that drop right in. The LA valve train is way more stable than the Stud mount of the magnum set up. Mine is now 410 CI of Twin Turbo Small Block Mopar!