The best budget set of heads would be found on 86-91 318 passenger cars and trucks. Teh casting number ends in "302". They have 318 sized intake ports, and a much better exh port, and are based on a closed chamber and high swirl properties. Take those heads, and bolt them on. All intkaes fit, all valvetrain bolts up, they add about .5 a pt of compression(more with the thin gaskets) and can be found very cheap. However, when you buy them from a bone yard, make sure there is an exchange policy if they are cracked, and have them magnafluxed to be sure. A hotter version is to have 360 sized 1.88/1.60 valves installed, and some minor bolw blending done to smooth the transition between the larger seats and throat. The Magnum heads are one of the best by far, but need some special attention to just "slap them on". the 302s give some of the good stuff, and need no modifications to install. Keep in mind, a 318 is only giving up 22" of bore size to a 340, and they will run just as hard, but you need to do a little more homework before you can embarass the 340 crowd.
