I have a 90 roller motor set up, but with carb and points dist(autolite, single vacuum advance). I played with the timing to get it to both idle fine and hold revs(in neutral) well. I had it set at 10 degrees btdc which idle'd ok but ran like crap with any throttle, so I backed it down closer to 0(guess) However, I cannot use the vacuum advance. When I hook it to the timed port, it idles fine, but when you throttle it it seems it overadvances and starts 'missing'(shaking). If I hook it to manifold vacuum it just dies immediately. The vacuum canister does hold vacuum, so I don't think it's a leak. So, which port do I use(ported or full vacuum), and what do you suggest the problems could be? Do you always set the timing with the advance unplugged?