Hello from Atlanta, Ga, Pokey!  It sounds like a bad starter----BusDepot has
a wonderful NEW Bosch starter for 80-81 manual transmissions on their
bargain page for US$99.99---  Compare this to a FLAPS rebuild for
$US70.00....  Do however check all your electrical connections for tightness
and corrosion---a wire brush to them and a retightening works wonders on old
and new starters.  Good luck!

Regards,
Mike Nichols
2--'81's