Won’t stop missing!

I have a '65 Barracuda that someone (I am sure he would not take credit) has put a '70-'74 318 into. The car is missing when I am driving down the road & the motor shakes quite noticeably when I hold the idle around 2000 rpms in park. I DO NOT have a timing tab so I am not able to tell anyone what the timing is set at. The car starts on the first turn, runs fine at idle, starts once it is hot & does not ping at all. I have replaced just about everything, new cap, rotor, points, condenser, plugs, wires, vacuum advance canister & carburetor. The vacuum advance that was on it would not hold any vacuum so I replaced it. It is an Edelbrock 650 with an electric choke. We adjusted the idle & mixture with a vacuum gauge & are getting around 19. The vacuum advance is hooked up to the timed port on the passenger's side of the carb. The motor runs perfect & smooth as glass with the vacuum advance unhooked & the port plugged. I really would prefer to use the vacuum advance especially with gas at almost $3. Any ideas? Could the timing cause this problem? As I said the motor does not ping & there are no issues with starting it once it is hot like you would normally have with bad timing. Could I loosen the distributor, turn it a bit & try it? I should be able to tell just revving it to around 2000 & seeing if it shakes. Could I just hold the revs up & turn the distributor to see if it will smooth out?

Will a switch to electronic ignition fix this? I have a buddy with a distributor, control module & voltage regulator that he said I can have; all I would need is a wiring harness & some instructions.

Every time I try to take this car anywhere but around the neighborhood something happens & it is really getting frustrating that I can not enjoy it.

I really appreciate any and all ideas, suggestions or advice. Thanks to everyone in advance.
Author: admin