It depends on how aggressive you want to get. At the very least, you could break out your timing light and see how far you could advance the timing and avoid detonation. One member found that advancing the initial timing 6 degrees helped add low end torque and picked up a few mpg.
A K&N or low restriction paper air filter, a set of Hooker 2143 Super Comp headers and dual exhausts should help. You might also try a multi spark box, like MSD's 6A to make sure you're lighting the fire as best you can. I would recommend using a wide band oxygen sensor to rejet the carb after you do this.
If you really want to go wild, you could play with the heads, smooth out the ports and add a 3 angle valve job. Its tricky but it may help.
There also may be some benefit in the Edelbrock Performer intake manifold and a 390cfm Holley 4160 carburetor. But you may find that while you pick up a little power, you lose mileage.
A Comp 240H grind cam also MIGHT help.