i have a 72 chevelle with a 307. the motor has 600 cfm edelbrock carb headers and flowmaster exhaust. it is backed by a rebuilt th350 with shift kit. the rear is a stock open rear with what i believe is 2.73 gears. i currently run a 16.053, is this a good time for my setup? what can i do that is relatively inexpensive to get into the 15's? will advancing the timing help at all? this is my first car and i am on a limited budget.

That's a respectable time for a 307 with those gears. Better gears will drop it into the 15's easily but it will cost you a few bucks to do. Play with your timing a little bit, see where it runs the best at. Toss that points distributor and install an HEI setup from a 75-80 vehicle.

You are very close to the high 15's/ Play with timing and carb jetting. But as already mentioned, what you really need is a deeper rear gear. A mild high stall torque converter could also help for several hundred less than getting rear gears set up.