As I remember . . . the Explorer backing plates have the same bolt pattern and center hole as the large bearing Torino axle housings. All you should need is a complete set of Explorer brakes and the spacer that goes between the axle bearing and the axle flange. A complete kit would look like this:

http://www.currieenterprises.com/ces...E.aspx?id=1229

The spacer is critical. If you don't use it, the axle can move in an out of the housing by about 1/4". Not good.

What I don't remember is how the brakespace offset worked out on my '34. (That's the distance between the axle housing flange and the axle flange with the axle fully inserted.)