Mild-Mannered 440 Mauler - Part 4, The Top End Build

Before the heads are bolted on, a bead of silicone is applied to the valley plate to seal it to the heads. We first trial fit the heads, and marked a line with a felt pen showing where the heads meet the plate.

Just before installing the cylinder heads, the tops of the copper head gaskets were given a smear of sealant, as needed, and then our monsters from Indy were guided over the studs. We found that four of the head studs from our standard Milodon 440 set, one above each pair of intake ports, were too short with the Indy castings. These were replaced with studs measuring 511/44 inches.

Indy's EZ heads, with their raised intake runners and longer valves, require longer pushrods. We measured the length required for our block and valvetrain combo, and ordered a set of 31/48-inch pushrods from Smith Brothers.

Custom high ratio 1.7:1 Harland Sharp roller rockers move the valves in a hurry, achieving a serious .600-inch lift from our Comp Cams flat-tappet cam. The valves were adjusted to just a nudge of about one-eighth of a turn past zero lash, giving just a minimum of preload for quiet operation.

We found the intake manifold exhaust cross over hit the valley inspection cover fasteners. We ground some clearance, and swapped to a button head fastener to solve that issue. The EZ heads have no provision to run manifold heat, and we'd recommend blocking it if they had.

Our buddy Roger Helgesen scored these fabricated sheetmetal valve covers at a swap meet, and when we were caught eyeing them at his shop, he said we could have them. We have no idea who made them, but some of the welds look questionable, so we're not sure they'll stay on the engine, but a trial fit was encouraging, and they did look good. Breathers will have to be installed before we run the engine.

Twelve bolts secure the access cover in the Indy valley plate. A bead of silicone provides the seal, though Indy offers a gasket (PN 228).

The Indy 440-2D RB intake manifold is by far the highest flowing two-plane we've ever tested. The large ports are easily matched to the EZ 295's port size. The two-plane configuration should be worth torque, and improve idle quality and vacuum slightly, but we hope to also try an Indy 440-2 RB 4150-series single-plane manifold.

Both of the larger CNC EZ heads required external oiling. We were surprised to hear from Russ Flagle, who along with his brother Fred, founded Indy Cylinder Head, that some customers are apprehensive about this additional mod. Plumbing it up takes a couple of minutes, thanks to Indy's well thought out kit (PN 440-10), and the convenient oil gallery at the rear of a Mopar big-block. The procedure is about as tricky as hooking up your garden hose.