Disconnecting secondaries

Not sure exactly what your rig weighs Mike, figuring it's on a G20/G30 chassis. The reason i'm against doing away with the secd operation is, if you have to pull some good size hills or pass someone, your asking a awful lot from a low comp. 350 on just those little primaries. 99% of the time you shouldn't be into the secondaries anyway.

Also, wouldn't hurt to check your vacuum advance canister to make sure it's operational. If not, that could really hurt your cruise mileage.