Get under the car and locate the shift rod that attaches to the lever on the transmission. The rod should have a bushing around it to fit tightly on the lever. Most fall off over the years leaving wasted motion in that rod. I've used a door hinge bushing kit sold by AutoZone for older Chevy trucks. It has an assortment of brass bushings. One will work, then I use a thin wave washer as well. That rod is adjustable just below the brake booster. A cross shaft comes from the exhaust manifold over to the frame. That rod is held in place by a nut at its upper end. Loosen nut, gently slide the rod into position.