Sometimes for one reason or another, projects can take a turn midstream, and in the case of our 446 build, timing and circumstance have led to just that. With our robust short-block built, fitting the top-end package marked the home stretch for our build-up. Our cylinder head criteria was to use aftermarket aluminum heads with relatively large Max Wedge ports, and we sought very high flow. We had planned on a set of extensively modified MP 383/440 replacement heads. in seeking to make these basic castings fit our requirements, the heads were radically ported, including filling in the pushrod pinch and cutting the as-cast intake ports to the maximum cross-sectional area. When we saw the new Indy 440-EZ heads at the recent trade shows, we began to rethink the practicality of our original approach.
Enter The Indy EZ
The 440-EZ series is based upon the popular Indy SR series of heads, but with casting revisions to the intake, and a relocated exhaust port, putting the exhaust back to the stock location from the raised SR position. The stock exhaust location eliminates potential complications in fitting existing header designs in most applications, but what really got our attention was the EZ performance potential. We had scores of hours of porting time in our low-port MP heads, and achieved respectable flow, but the new Indy heads offered something our highly modified castings couldn't match-power and performance right out of the box. Weighing which approach would better serve those looking to duplicate our effort, the cold reality is our insanely modified castings represented more work and one-off esoteric mods than even we'd ever want to attempt again, much less pay for. The architecture of the Indy head was designed from the onset with large high-flowing ports in mind. With the raised intake runners working down the port to Indy's trademark long valves, the layout has distinct performance advantages, including a taller, deeper, port in the bowl and short turn, and a more appropriately sized port volume for a big-block engine. The Indy heads free up the area under the spring seat, which is critically short in production-style short-valve heads. The clincher was a look at the flow numbers.
Indy offers the 440-EZ head in four versions, covering applications over a wide performance level. The most basic version is the standard 440-EZ, which retains the factory port window size at the manifold flange to mate with any standard factory or aftermarket intake manifold. The EZ heads preserve the factory layout for the pushrod location and rocker arms, and oil the rockers through the heads, just like the originals. Basically, all that is required are longer pushrods and the Indy valley plate to make the swap a bolt-on. Helped by the streamlined shape afforded by Indy's long-valve, and an ample 2.19-inch valve diameter, the as-cast 270cc 440-EZ intake ports flow 305 cfm, while the exhaust handles 215 cfm. With a flow gain approaching 40 percent as compared to stock castings, there's tremendous power potential in these heads. That's very good, but Indy offers three even hotter versions of the EZ head in the Max Wedge port window configuration.
If more flow is called for, Indy opens the EZ head to larger proportions with the 440 EZ-1, with CNC porting to the bowls and intake runner opening, taking the head to a Max-Wedge-size port window, with a port volume of 275 cc. The larger intake port opening and CNC work raise the intake flow to the 3TK level, and allow the use of higher-capacity factory or Indy Max-wedge intake manifolds. The EZ-1 is otherwise the same as the standard EZ head, in regard to stock rocker oiling and the standard location exhaust.