I have a 73 with a 351 Windsor and also a 2 barrel carb as well. Mine was doing the same thing. Start off with the most inexpensive route which would be your basic spray can of carb cleaner. Take the air cleaner and all that stuff off until you just see the carb. Turn the car on, use your hand to pull the throttle cable enough to raise the RPM then spray the cleaner into the carb. The RPM's will drop while you do this and try to flood the carb out, just give it more gas as you spray. Also, while you have the carb exposed, take the carb cleaner and spray along all 4 sides of the bottom of the carb where it attaches itself to the manifold. If the RPM's jump up, then the seal to your carb is no good and has to be replaced. The gasket itself is extremely expensive and it a repair you can do within a half hour tops. If the seal is good, you've cleaned out the carb with the spray cleaner and it still lacks in power, then the fuel jet in the carb is either bad or has junk build up in it. The least expensive way to go about that first would be to just pick up some of that carb/injector cleaner you can get at just about any gas station. You just pour it into a full tank of gas. If that still doesn't work (like whats happening to me), and you dont want to shell out the cash for a new carb, you can get carb rebuild kits that come with all new gaskets, seals, springs and fuel jets. That will run you about 40 to 50 bucks for the kit with everything. The rebuild kit is simple enough to do yourself, but make sure you have a good hour or two to commit to it. Its a very tedious job and takes alot of attention because you have to make sure that all the parts go right back in the right place or you will seriously damage your carb. If you dont want to go through the hassle, then an OEM 2 barrel carb will run you about 239 bucks. I hope this helps.