472, here is some "insider" info on these crate Hemis - this is the best answer I could get. The sources are all retired from Chrysler now, or have retired/sold off their businesses that did work for Chrysler:

We introduced the Hemi Crate motors in the late 1990's. This included the 472-inch version (rated at about 525hp with a single 4BBL carb - not included). These crate engines were built with all Chrysler (Mopar Performance) parts - blocks, cranks, rods, pistons, cams & valvetrain, heads and intakes. After the big layoffs of 2001, MP stopped selling their own rods and pistons, so by 2010 these parts would have been aftermarket parts. MP stopped making performance parts catalogs in the early 2000's which makes tracking these details very difficult. Slowly MP stopped making the own parts, which were replaced by aftermarket parts. The engine builders changed several times also. It's a lot easier to look at the actual parts (casting numbers on blocks, heads, intakes) than to try to track them down from to engine builder to the car.

Thanks!