best bolt on

I was wondering what is the best fairly cheap bolt on part for a 73 SB with a 1600cc motor. I have a jacobs performance ing, but i really see no difference in giddy-up.
mike

Best way to increase oomph from any engine is to put more in and get more out.

Bigger (or dual) carbs and a flow through exhaust.

the exhaust thing is something i was curious about. how much more power can you get through exhaust changes? that big a difference or is it usually in conjunction with upgrades?