Proportioning valve question

You can do that and through experimentation maybe come up with a combo that stops better than stock.

Or...

You can use the decades of engineering that went into the factory setup.


If you go 73 up single piston large built pattern then the 73 up master and 73 up combo valve would be the way to go

If staying sbp I would go with KH and related parts.
RMS may be the deciding factor. Think the axles are not selectable. In fact they may require disk brakes. If so then I wasted more of my time.
I do like your prospective. It's just two choices.