If you know you have spark at all the plugs, has good compression, you've set the timing and rebuilt the carb with sucess. Whats the problem?

IMO, if the distributor was set up from the factory / original to the vehicle and it runs right, I'd leave it alone. I'd check that the vac advance is working, connect direct manifold vacuum to the vacuum advance and start the truck, it should idle at a higher rpm than normal. If it does reconnect the vac hose to its original vac port and leave it. Otherwise you might get lost in trying to tune it for an extra hp or two thats not there. Good luck though with whatever decide to do