Jerry:
I'll be quite interested in your degree-wheel checks. I stared at the CCS-1 and Elgin cam specs till my eyes blurred. I couldn't figure out how theit published specs relate to the factory specs from the manual. Which specs include the clearance ramps? What would be the duration at 0.050"?
Anyhow I used the Crower cam I already have along with its lifters. That cam is at the hairy edge of what's usable for my purposes -- hauling a camper at highway speeds. It's a split-overlap cam, advanced 4 degrees when ground. Duration at 0.050 is 220 degrees while advertised duration is 252 with 0.020 valve lash.
The result is that at 2500 RPM the engine is just barely "up on the cam" and is much happier running at 2800. Sixty MPH is 2500 RPM in overdrive. Before I changed axle gear ratio from 5.13 to 4.57 sixty MPH was 2850. Since I can't go back to the 5.13 (it is worn out) I'm thinking of changing cams, but to what? I want one that pulls at 2500.
I just finished a 4,000 mile road trip with the camper here in the Western US -- Washington State to Southern Arizona and back. Lots of mountains, lots of flat straights, lots of wind. So on-the-road experience is now well established. I'd like to get the fuel consumption down before I head for the Civil War battle grounds in your area. It's 10MPG now.
FWIW, when I changed cams from a mild Howard's grind to the Crower my gas mileage went up 25% with no other changes. My theory is that I was running so far above the torque peak that specific fuel consumption was way up. Now I think I'm 3-400 RPM below the torque peak so fuel economy suffers.
