Yeah before you start pulling axles there are a few thjings to improve first. Although gears is a definate increse in acceleration, it will suffer in mileage driveability etc.
Previous advice is good. There are 3 things that you can easily do:
1. I would upgade the ignition to a good electronic sytem. Contact Don at FBO Systems who designed and produced a killer mopar electronic ignition system that is a direct replacement of your current system. ie if you have an electronic ignition, there is no rewiring necessary just swap the distributor, coil, and the brain box and go have fun. I have personally used his equipment and for a street car it is as good or better that a jacobs, mallory, etc system. This thing looks stock and it works. Plus he'll re-curve your distribtor which is also a big help. Check out
www.4secondsflat.com for details.
2. Exhaust! put some true duals on that sucker! If you have not already...this will reduce backpressure and increase flow. As with everything if you have the money get a 2 1/2" mandrel bent system with "X" pipe and headers. If not even a basic dual sytem from manifolds to tail pipes would help. Plus it sounds cool!
3. This is sort of in line with 1 but re adjust your timing. The 72 cars were way retarded in timing. Most were set around TDC or below. Make sure the car is warm and blocked. Start the car in idle with the vacum advance port plugged and a vacum gage in a manifold port and a timing light. If you don't have a vacum gage then go get one because next to a timing light it is one of the most useful tools we gearheads can use. Set initial timing @ idle to around 12 degrees BTDC. You should notice an imediate improvement in throttle response and the car should pick up in idle. In fact after timing is set you should reset the idle and mixture on the carb becaue it my need a bit more juice. Usually this is a pretty good setup to setting timing. If you really want to fine tune it you can run the motor up to about 2500RPM and adjust the total timing to around 34 degrees BTDC but this can be hard to do if you are by yourself. I've found that by setting it initially @ 12 BTDC you get farily close to 34 total + or - 2 degrees. This will probably be the most noticeable jump. If it is still close to stock it should run like a raped ape when it is set properly. If the car starts to detonate then it is advanced too far and it needs to be brought back. I did this on my puny 2BBl 318 before the rebuild and man what a difference. The same does apply for big blocks too.
Beyond these basic things you start looking at gears, shift kits, rebuilds, torque converters, etc. But for starters these 3 should give noticeable improvement.