I know the engine and also what it made in 2010, and yes Randy is the real deal when it comes to Holleys. I believe he worked for Holley . Randy also did his thing to the Magnum RT heads on that engine which I'm sure was skillful.
In every instance did all three metrics improve with the larger carbs? As in best 60ft/ET/MPH?
Is it possible that on a underheaded large cube stout engine that the larger carbs slowed down the overall intake tract airspeed? Mixture quality aside. Also to move to a 4500 you had to have used an adapter of some kind--was something similar used on the 4150's? Just curious. J.Rob
