there is a pretty simple recipe for 300 horse. This includes nice aluminum heads, better intake (RPM, Stealth, etc.), and a matching cam. Along as you have the other compliments such as a properly tuned carb, headers, etc. That should get you to 300 horse. As far as money is concerned, horsepower costs money so you'll need to spend some of it. Typically aluminum heads run 1000, intake 175, cam 200 (all rough estimates). Not to mention all of the little stuff such as gaskets, rocker arms, pushrods, etc. I'm not trying to discourage you just be realistic going in. Builds usually cost more than expected. Ask me how I know! Also, what are your goals (drag, street/strip, autocross, sreet) for the car. That will help the guys when making parts recommendations. Also, tell us if it's a stick or auto, whether it has gears, all the good info. All together 300 hp isn't too difficult, just takes the right planned out approach.