Having an issue with the vacuum advance being fully on. It does not change even when I turn the distributor either direction. Engine starts ok, sometimes with a slight hesitation when turning over. Idles ok without stalling at 450 RPM's, Hydra-Matic RPM.

I have properly set the timing making sure #1 is on the compression stroke and set on the BB on the flywheel. Have even tried setting the timing it a little before the BB.
Distributor is set in the engine so that it aligns with the oil pump slot.
Made sure the distributor wires are in the correct firing order and #1 in the correct location on the cap.
Carburetor is installed correctly with the insulator in the correct position.
Have tried setting the idle mixture screw at 1 1/2, 2, 2 1/2 turns on the carburetor.
Have new manifold gaskets and are properly tighten.

Fresh rebuilt 1960 235 truck engine.
Carburetor Rochester B as in the Truck Repair Manual page 6-52. Although mine is stamped C Rochester GM it looks the same.


1954 Chevy 3104 3 Window Hydra-Matic in my family for over 60 Years

Once in a while you get shown the light in the strangest of places if you look at it right... "Scarlet Begonias" Grateful Dead 1974