Originally Posted by Custom10
The cruise RPM he listed was low about 2300 if I remember, now every engine will have its own characteristics but at that RPM with the cam he is running 20" does seem high. From my experience with my 383 and a 221 duration cam at 50 thou (less duration than his) I am pulling only about 14-15" at that RPM at a steady state cruise, the only time I come to 20" is if I am off the pedal and the gearing is causing the truck to decelerate but I have an 1405eddy and am on manifold vacuum. That is why I asked about checking his vac gage to be sure it was accurate. If the gage is off then it will hamper his tuning setup.
Same here. My brake canister is usually 10-15 reserve vac, rarely gets higher on my 383