For the second time in 20 thousand miles I need a new distirbutor, it has worn the gear out but the really strange part is that the gear is good on one side and 180 around the teeth are almost gone, has anyone ever experieinced this?

 

I've seen this a number of times. It is most likely related to the distributer drive shaft between the oil pump and distributer or the oil pump itself. Replace the Shaft and Oil Pump along with the new Gear. When You do this, make sure that the distributer is setting properly in place. Check the height at which the dist meets the intake manifold. It should set in with about 1/16 - 1/8 inch clearance vertically without a dist. gasket. If not, if it bottoms out or doesn't go all the way down, You must find out what the interference is. A binding oil pump or bent ( even very slightly ) shaft or too heavy of oil viscoscity will lead to failure. Make sure You check the gear on the camshaft also for odd wear. If it shows the same pattern as Your distributer gear, You must also replace the camshaft and tappets. This isn'y always a simple problem, so don't leave any stone unturned. Use a premium gear, if You are using a flat tappet
( solid or hydraulic ) then use a steel distributer gear. The only time to use a brass gear is on a steel billet ( racing application ) solid roller tappet camshaft core. Good luck.