ok I removed the three screws on the side of the distributor that hold the vacuum advance in, but the linkage that goes in to the distributor is still attached and I don't see how to disconnect it.

the engine is a 318 210hp
the truck is a 1968 3/4 ton camper special

 

there is a rod that comes out of the advance that has a tip on the end of the rod. the tip goes into the plate that holds the points/reluctor. you might have to unscrew that plate to let the tip slide out of that plate.

 

thanks, i didnt realize i had to unscrew the plate