yet another 318 cam /head question

I think you should get a bit more gear, cam and spend some time tuning it. a converter might be worthwhile too.

right now im running a stock bottom end 73 318 with a 340 cam and ld4b with a 600cfm edelbrock, dual exhaust with stock 318 manifolds. Man this thing has some nuts and I think i could tune it better. I have the stock converter as well but im going 4 speed when i have time to do the swap so i refuse to waste money on a converter.

I know early heads were set up for lead gas, so i dont know if your losing power there. from what i understand they did not have hardened seats. maybe someone could shed more light on that area. If they are an issue id get some cheap heads, or freshen what you have whatever is cheaper. it sounds like you want to go with another motor in the next few years, so i would spend as little as possible. Definatly think about messing with your carb and distributer for the perfect tune. This should be a cheap way to get a few hp.