my post was one of confusion since we had discussed this problem via the PM system before brunsrubber ever posted his first post on HR.
1987 is a cross over year for the valve bodies on the 700 / 4L60 trans. there are early and late designs.
Early design with NO aux v-body.
early design with a aux v-body
Late design with aux v-body.
You must be careful of parts mismatch and check balls used with each design.