Constant corosion on + battery terminal?

[David]

I'm constantly battling heavy corosion buildup on the + battery terminal. It's been that way since I bought her 4 years ago.  I have to remove the battery and clean everything about every 4-6 months. It has actually eaten away much of the copper on the battery cable connector, to the point I will have to replace it soon.  The negative terminal always looks perfect. This is the only car I've every had with a problem like this...thoughts?

Dave
1987 CGT 2.3
SE VA