This doesn't sound like a timing problem unless it's way off. When did you first start having the problem?
You should still rule it out, you can get your top dead fairly easy. It's called static timing, then you can install the timing tape purchased from any Mopar engine performance supplier then go ahead and time with the light. Just remove the number one spark plug, pull the dist cap off and bump the engine to where the rotor is just coming up towards #1 and make sure the piston is coming up on compression stroke, once you have it top dead on number one (not by the distributor rotor but by the piston travel), mark the dampner to corraspond with your pointer. You may just find your mark if you do that and you could mark it so you can read it better. White shows up well with the timing light. There are a lot of other things that could mess you up too, I have a 360 with a worn out timing chain, if I back off from TDC then turn it back the other way, it takes 7 1/2 degrees before the rotor will turn, it won't idle worth a darn, especially when it's cold. Lots of things could cause the problem. You can check your timing chain when you set your static TDC. If you back it off then rotate it in the correct rotation again, the distributor should move with only very little movement of the crankshaft. Many other things could cause your problem too as Chryco said, the carb is a good place to look, Vacuum leaks etc. Good Luck!
