This D&P customer ordered the ZZ572/620 Deluxe crate engine from GM Performance Parts. The Deluxe version includes the base ZZ572/620 engine, plus the following items: aluminum water pump, 850-cfm Demon carburetor, flexplate, HEI distributor, aluminum intake manifold, and red plug wires and looms. But it all boils down to power, which weighs in at 620 hp at 5,500 rpm and 650 lb-ft at 4,500 rpm. Before all that power can be dropped in, a few modifications are necessary. For one, you can see how shallow the firewall's bellhousing tunnel is. Because of this, blistering the firewall is a must.