81 Chevy you stated "you have the early valve body with transfer tube & aux. VB
"... So, you have TWO holes above the 1-2 sequence valve on the VB
????????? That would indicate an early (82-early 86 non-aux. VB
's) valve body.
While it is possible (I've seen it before) it is more likely that you have a single hole/late/auxillary valve body.
The pic that Crosley posted, you can leave out the check ball closest to the leading edge. Leaving it out will give a slightly more firm reverse apply. So slight you probably won't even notice a difference.