could be intake leak.....when you have tried everything else....might try that :Handshake while it is running, spray carb cleaner (I think) around the intake, if the idle changes.....you have found a leak.
Or starting fluid. If RPM goes up, you've found your leak. Some people say use soapy water also for the same effect, but RPM will go down with this method....
I use water,Starting fluid will tell you if you have Bad plug wires and pluck your facial hair for you.(ask me how I know)
Even If I Dial The Timing In By Ear Theres No Change, How Will The Starting Fluid Tell Me I Have Bad Plugs/wires
Update!!!! I Changed Gaskets On Carb And Plugged Vacuums. Now It Allows We To Idle It Lower Cool!! But When I Put In Into Gear I Still Breaks Like Its Not Firing On All Cylinders And When I Get On The Gas It Like Backfires And Fire Comes Out The Carb
I would just move the distributor around till the car ran better. Screw the actual timing issue, find a sweet spot that it will run, and go from there. Always assume that everything is wrong, and nothing is right. Sounds like you have the vacuum problem solved. Troubleshoot from there, eliminating and recording your way to success. Dan