Hmm....4 months you say? How old is the gas in the car? If it's more than 4-5 months old, I'd bet it's bad gas. Gas nowadays don't last very long at all. Drain your tank and line and make sure your carb jets are squirting gas when you move the throttle linkage. It may have also schlaqued on you too including inside the fuel line and plugged it up quite a bit. If it did, it will run lean and could also backfire through the intake or exhaust. The schlaqued gas could also gum up your Carb (which is why I said to verify that your jets are pumping gas) and/or cause your intake and exhaust valves to stick. One thing that you might try to free the valves (and this is really no joke here, I had to do the exact same thing last spring when I started my '55 for the first time in 6 months) start the engine and SLOWLY pour a SMALL amount (no more than half a quart) of Automatic Transmission Fluid into the carburetor. Don't let the engine die while you are doing this or you'll have fouled plugs.

It sounds wrong I know; but, what will happen is that when the ATF burns in the cylinder, believe it or not, it will lubricate the valve stems and can free them up. If this is the problem, it could be solved for as little as the cost of a half a quart of ATF fluid. It may not too; but, before I'd go pulling anything, it is something I would definitely try.

Good Luck,
Dutch