How do install a cam and get the timing right on a 305?
if the engine is removed from vehicle you need to remove the intake, the valve covers, the rocker arms, pushrods, and lifters; then you remove the timing cover, then line up the marks on the sprockets by turning the engine over by hand, then remove the cam and crank sprockets and timing chain; then pull out the cam and install the new one; line up the marks on the sprockets and reinstall them turning the cam if necessary; reverse the rest of the procedure.