As already stated, the super or ultra sprags have six tapped holes where two additional holes have to be drilled in the case. The placement of these holes can either be marked out manually or one can purchase a jig from A&A to help with drilling these two holes.

http://www.aandatrans.com/Departments/Chrysler-727-Trans/Bolt-In-Sprag.aspx?page=3

Drilling these holes on an older case is not a problem but on the later cases, there is a boss that you have to drill through and needs to be counterbored in order to make room for the socket head capscrew. This can be done on a mill or one can use a counterbore reamer to clearance the holes after the through holes are drilled.