We were certainly happy to see almost 800 horsepower on the dyno, but quite frankly we were a little surprised that this combination made the power that it did. The last time we ran this engine we saw 805 horsepower, but in that series of tests we were running a bigger camshaft with 10 degrees more duration at .050 inch, and over .120-inch more lift. We did change ignition systems since that last test and we changed to the dry-sump setup, so maybe those changes picked up some power that was lost by going with the smaller camshaft? Originally we planned to continue the testing to see if we could better understand the changes that we had made, but the post test teardown revealed some cracks in the main webs. Not to worry, though; we have already ordered up a new block from the local Dodge dealer so we'll be back bigger and better before too long.
Mopar Performance has re-released a single carburetor intake that fits the Max Wedge heads on an RB block. This M1 intake, part number P4876337, had been discontinued for awhile but it is now back in the catalog. The 337 intake has a unique cast-in valley floor, which allows it to be installed without using a traditional bathtub type intake gasket. The other interesting feature of the 337 manifold is that it is a very low-rise design so it might just fit under a stock hood.
We had been curious about the potential of this intake manifold for some time so we decided to run some tests while we had Project 505 on the dyno. The intake quickly bolted on with a pair of Max Wedge gaskets, but we needed to use a 4150 to 4500 carburetor base adapter since we wanted to stay with the same Dominator that we had been using for the other dyno pulls. We assumed this low-rise intake manifold would be down on power from the taller Super Victor, so when the dyno readout showed that we had lost 15 horsepower, we weren't overly surprised. But then the dyno operator decided to run the engine at a slightly higher engine speed to see what would happen, and we about fell off of our chair when the motor picked up significant power. We actually saw the best power numbers of the session with a 797 horsepower reading at 7,300 rpm. Evidently the shorter runners on the 337 intake wanted a little more engine speed before they hit their stride. We usually never turn this motor past 7,000 rpm since the peak power has always been down in the 6,500 range, but now we know that this particular combination works better at higher speeds.