The 76 I'm picking up is knocking and needs to be torn out to get fixed so I figured I should build it while I have the chance instead of later. It's got the 4 speed transmission. I'd like to have a streetable car but still be able to lite my tires and leave some people behind. What is the main few things holding these 302's back from making horsepower? Will newer age heads work on the old style block? Anything I should expect?