i have a 73 L48 car.  i know that it will benefit from breathing better (headers and exhaust), but separate from that, what are the performance mods that give the most for the dollar?

That's the eternal question..it depends on many factors..one being how stock do you want the car to be..is the car original now..if it is bolt ons are the easiest thing to do ie headers..HEI ignition..if not you have to play with the C's..cam carb compression..the carb is the easiest one but won't do much without the cam and that is limited by compression..so here we are at how much is bang for the buck..with headers giving about 15 - 20 HP if matched to the current setup..costing anywhere from 200 or so to whatever you want to spend can be a high yield option..but if you want more you spend more to change the entire dynamics of the engine..so a good pair of headers yields a good amount for what you pay but have limited long lasting affects over time..one being gas mileage..because the car is faster and louder one can't keep the right foot out of it..and under hood temps increase and that can lead to a hotter interior and fuel issues like vapor lock..have fun with it when it's fast though I know I do also!
Rich

\\\\\\\\\\\\\\\\\\\\\thanks for th reply.  going the route of ceramic coated headers which should help with temps.  it's really a therapeutic car so i don't really care about mileage or heat, just the fun factor.  you've pretty much confirmed what i was thinking (the 3 c's). 

If you are going to go with the 3 Cs, get a matched intake set up. Edelbrock's Performer series kits work well and their carbs are very user friendly...

You nailed it Paul..getting a kit like that with the cam intake and carb matched up work great..I like Edelbrock kits..a good winter project.
Rich

thanks for the advice gentlemen, i appreciate it.  will let you know how it plays out.

I still say that the best bang for the buck is a Gernade.