72 Mustang Running Rough

first the distributor cannot be 180 out otherwise the engine would not run at all. second it sounds like you have a vacuum leak. torque the intake down and see if that helps any, as the leak may be on the under side of the intake. second, set the idle mixture screws to the smoothest idle you can get. you also need to set the idle speed(in drive if an automatic). ignition timing should be between 10 and 14 degrees initial. check the plugs, point setting, valve adjustment.

You are going to have to locate the timing marks. Use some paint or crayon to make it easy to see. You can't time your engine with out seeing the marks. Do you have your dwell time set to specs? Unless you want to keep your car original, save your self alot of head aches and use electronic distributor. Sound like a vacuum leak is your main issue. Be careful on over tightening intake bolts as you can break bolts and manifolds that way. That Edelbrock carb uses 7psi max. fuel pressure. If your floats aren't set right or running Holley fuel pumps could be flooding.