In mid 1987 GM built some weird combos on the 700r4... early 700r4 had no aux v-body and transfer tube...
then they used the early design main v-body with the aux v-body and transfer tube...
then late 1987 they used the updated main v-body with aux v-body and transfer tube.
Different check ball locations per main v-body design and aux v-body or not. Gm was trying to act like Ford or something in 1987 with the 700r4 transmittin
Dont worry how old you are... it is the mileage on your body that adds up.