It all starts with a clean 440 block. Ours came from a '69 Chrysler New Yorker. Weighing 213 pounds with caps, it's about 70 pounds lighter than a 426 Hemi block. Preparation includes pressure testing, magnetic crack detection, fresh cam bearings, and a 0.030 overbore for a finished bore size of 4.350 inches. Stock Hemi and wedge motor mounts are no-go. You'll need to use elephant ear mounts for vehicle installation. The mounting lugs on the driver side must be removed for Hemi header clearance; the passenger side lugs (shown) can stay.