ok, now it won't start. the wires are in the correct order. the rotor button is on number one wire on the cap and the harmonic mark is facing the passenger side of the truck I've messed with the timing on it so much, I'm afraid I can't set it back correctly. I guess I need to get a mechanic out here.Vacuum advance isn't needed. As a matter of fact a majority of the 413 and 440 engines run better with the vacuum advance plugged off. Remember, vacuum advance slowly advances the timing at cruise (especially) and during high vacuum, so low rpm the vacuum advance reduces itself, so, since big blocks like slower advance to begin with, the extra advance even at cruise isn't needed.
Go back to basics. Check the firing order first, make sure that is correct, then check the top dead center mark on the harmonic balancer, then pop the cap and see if it is pointing at number 1 or number 6 (both are good but still need to be close to one of the two wires), then grab the harmonic balancer and rock it to see if there is a bunch of play there. Play indicates a worn timing chain, which does make the timing bounce around a lot, or makes the valves open later and close later than they should. Next thing is to see how things look inside the distributor itself, no contaminants, not floating metal junk, twist the rotor and see if there is some movement with spring pressure that returns it to its original position (this needs to be kind of firm, but too tight is just as bad as too soft).