Mopar [HEAD] Aches PLZ HELP!?

Are these the heads that are on your car at the moment?
3671587 1973-1976 340 360 1.88" 1.60" 65cc-73cc

You can pull valve cover and find casting number. If so, considering the budjet you mentioned, you have a couple of choices. First you need to find if size of intake runners matches 318 heads, or the larger 360 heads. Are pistons in engine now zero decked, or down in the hole?
In my opinion, your choices are to mill the heads you have now and port match them with your intake, or to get 302 heads, which have a smaller chamber size, increasing compression, and port matching them to your intake.
I recently bought a set of 340/360 J heads, and a set of 302 heads for my 318, and after doing considerable research on which would be the best for my street car, as BJR stated above, decided the 302s would be best for my application. I'm port matching the intake to heads, and doing some other minor home porting, adding thin MP head gaskets, and installing. I purchased the freshened 302 heads for right around $200. Just for a heads-up, there was an ad on this forum yesterday, of a person wanting to sell a set of 302 heads pretty cheap. Do a search of 302 heads, and you should find it right away. Hope this helps, Mike