Remove the distributor cap. Put a wrench on the crankshaft balancer bolt. Turn the crank until the marker comes to top dead center. Mark on the distributor where the rotor is pointing. Turn the crank in the opposite direction while keeping an eye on the dist. rotor. Stop turning the crank when the rotor just starts to move. Look on the crank pulley and compare the number of degrees the marker moved from TDC. If it is more than 7 degrees then the timing gears and chains must be replaced. You will never be able to control timing otherwise.
Also the distributor shaft bushings wear rapidly on such a short shaft which throws the point dwell and gap out of specifications causing misses and lack of power.