Because longevity was a concern, we left the guides alone so as not to jeopardize valve stability. A lot of attention to detail was paid to the combustion chambers and making sure the valves were unshrouded. Also, the sharp edges left from where the seats were inserted into the head were smoothed and blended. We've found that a multi-angle valve job where the edges on the top of both the intake and exhaust valves are radiused and smoothed really helps with low-lift exhaust flow and relieves any possible hot spots that could lead to detonation. The intake was also cleaned and squared with a sanding roll, but no other modifications were made.
Back on the dyno, the pulls yielded 652 hp at 6,100 rpm and 623 lb-ft at 4,700 rpm with over 600 lb-ft of torque being maintained between 4,100 and 5,600 rpm. That is one flat torque curve. The minimal porting job gained 34 hp and 26 lb-ft of torque-well worth the effort.
We were so excited with how the RPM heads performed, we called a friend in Edelbrock's engineering department to share the good news. He told us the engine would be a perfect testbed for the new Victor 440 heads Edelbrock was about to release and asked if we would like to try a set. Are you kidding? We couldn't get to Edelbrock's Torrance, California, facility fast enough.
The new Victor 440 heads have raised intake and exhaust ports. The exhaust ports have been moved up 0.250 inch while the intake ports have been raised a whopping 0.650 inch. The intake-valve sizes have also been increased to 2.20 inches compared with the RPM heads at 2.14 inches. The heart-shaped combustion chambers are new and measure 75 cc. Edelbrock has also cast enough material into the heads that you can take the ports all the way out to Max Wedge size. What can only be described as cast-in spacers on the intake sides of the heads allow you to use your existing Victor 440 manifold when you make the swap. They come with valves and seals, but because most will be destined for racing applications, valvesprings are left up to the racer.
At the time we got the new set of heads, no one was making application-specific rocker arms for the Victor 440. Comp Cams and T&D Machine Products got together and fixed that problem and now offer rockers designed just for these heads. The exhaust rocker configuration didn't change much, but the larger-sized intake ports required that the intake rocker be offset for pushrod clearance.