Stock CUCV alternators (27SI) actually have five connections, including the isolated ground stud. However, as you know, the driver's side alternator (GEN1) does
not need an isolated ground, so you can use the DL7157 with no problems on that side. When looking at the rear side of the DL7157 alternator, the fourth connection is at the top left corner, hidden underneath a round rubber cap. Your stock alternators may be missing these rubber caps, but the connection points are in the same location.
If you stick with the DL7157, it produces 100-amps of output, which matches the stock alternators perfectly.