I tried both ported and manifold vacuum. At first if I hooked up to manifold, it would stumble at idle. And if I hooked it to ported(passenger side of the edelbrock carb) it would stumble when throttle was applied off idle. I used a piston stop to verify true top dead center and applied timing tape as the mark on the converter was a degree off. What I did after that was weld in a 1/4" washer(.062" thick), to limit vacuum pod travel by that much. What I will likely do is pull the vacuum advance pod and tack weld another washer to the backside of the vacuum pod to take a bit more travel out of it. Then I can set the Allen wrench back at most sensitive vacuum advance and reduce from there. It was so close to operating well with it, off idle was more crisp and felt a bit more powerful. The symptoms were random sputters/missfires between 2500-3000 on the highway, that went away above 3000 and 70 mph. After disconnecting the vacuum advance, this went away. I had the the pod turned 6 turns out from full advance at this point as well as the. 062" of travel removed from a 11 vacuum canister.