With the top-end in place, our 440 had a seriously purposeful look. We bolted on a Speed Demon carb, though we will be testing other Demon carbs including the Mighty Demon, since we do not anticipate needing a choke.
Though the Indy heads are offered fully assembled and ready to run, we elected to go with our choice of Comp's new beehive valvesprings (PN 26120). We've seen the beehives in action on other applications, typically hydraulic rollers, with impressive results. We have witnessed these springs dramatically increase rpm potential, while running at a reduced spring load, and were eager to give them a try in a Mopar flat-tappet hydraulic application. The beehive springs reduce spring mass, and the winding design makes the springs much less susceptible to harmonic spring surge, a primary factor in loss of valve control. Installed at 1.900 inches, the springs will provide 148 pounds of seat load, and 369 pounds of load over-the-nose with our cam combo. The Comp springs were installed with the required special retainers, and a set of Comp SuperLocks for the Indy 111/432-inch stem valves. Our cam combo would put them to the test, with the extraordinarily fast Comp XEHL hydraulic flat-tappet cam, and our selection of custom 1.7:1-ratio Harland Sharp rockers. With only 231-degrees of duration at .050-inch lift, our combo will open the valves to a maximum of just a hair under .600-inch, representing a very demanding combination. The aggressive number 5964 lobe our custom cam is based on may seem short on duration when the .050-inch number is quoted, but the duration at .200 inch is a healthy 149 degrees. We were after a short duration/high lift combo to maximize idle quality and vacuum in a tame street application.
The balance of our assembly included the excellent Indy 440-2D dual-plane intake manifold, ported and prepped in a previous issue to flow 360-plus-cfm. We will top the intake with a large Demon carburetor. Needless to say, we are going out on a limb with this unusual combination of large, high-flowing heads, combined with a very short duration, high-lift cam, and a large two-plane intake capped with a big four-barrel. The goal is an exceptionally good idle and strong torque, with impressive power into the lower 6,000-rpm range. We expect to put the theory to the test in a full dyno session in an upcoming issue. We'll sample several capacities of Demon carbs from Westech's inventory of dyno carburetors, and hope to experiment with an Indy single-plane intake, to see how the power at higher engine speeds responds. Will it work? We sure hope so, but you can bet we'll be packing a big solid roller stick as a back up, just in case we turn out to be all wet with our experiment. Hey, but it just may work. Stay tuned.
Indy's port shape owes a great deal to the use of longer valves than those used in production heads. Notice the difference between the stock-length valve (left), and the Indy valve (right). The longer valves allow for a taller, flow enhancing, short turn, and a deeper bowl with more cross-sectional area, as well as room for improved valvespring installed height. Many advantages here. | 
Indy sells the heads as complete assemblies, however, we wanted to try something different in springs. The package we used to fill out our heads included a set of Indy's valves, and Comp's trick beehive springs, locators, retainers, and locks. The special locators for Comp's beehive springs are not currently available in an inside diameter to match the .670-inch valveguide register on the Indy heads, so we had to machine the spring locators to fit. | 
Techline's thermal barrier coating was applied to the chamber side of the valves. We've found the coating here is a benefit in decreasing the octane requirement, helping reduce heat transfer to the mixture, especially from the exhaust valve. |
Why were we psyched? Maybe because when we put the Indy EZ 295 heads on the bench, they delivered the 355 cfm Indy quotes at .700-inch lift, and 360 cfm at .800-inch. We were also pleased to find the exhaust was well above the published numbers when tested with a flow tube. It's always good when a manufacturer's product delivers on their claim, and this is especially true in the often-exaggerated area of airflow. We were very impressed with the results turned in by Indy's Windjammer CNC porting, very substantial. | 
Our assembled short-block was eagerly awaiting the Indy top-end. The block is a retired dyno test unit, and had been fitted with copper O-rings at one time for nitrous testing. A set of Milodon studs was installed to provide the clamping. | 
Transferring the cams motion is a set of Comp's premium Pro Magnum hydraulic lifters. We applied some cam lube to the base and oil to the flanks, and slid them in place. When installing flat-tappet lifters, make certain that the lifters fit smoothly in the bores and rotate freely, without any binding or snagging. |
The Indy valley plate goes on before the heads. We favor the PN 440-6R R/B plate that allows access to the lifter valley, an important consideration if you ever need to get in there for a cam change or other purpose, since the plate becomes captive once the heads are installed. A light bead of silicone seals it to the block. Make sure the alignment is even to the block at all four corners. | 
To go with the O-ringed block, this ex-dyno engine requires copper gaskets. We have found these Milodon gaskets to provide a good reliable seal if properly installed. A glitch is that the two separate steam holes punched in the gasket, as shown, end up with one hole blind to the block and head. The fix is to cut a slot between the two holes, as shown in the gasket below. | 
A light smear of silicone around all the water or oil passages is applied to seal the copper gaskets to the fluids. The gaskets will likely leak if put on dry. Take the time to study how the block passages line up with the gaskets to be certain that the sealer is applied in all the areas needed. |