Had been thinking of fitting the GM B body full size front brake spindles that come with 12 inch discs. Found a list of suitable donor vehicles for the spindles online,seems it's a common upgrade in US. Spindles are supposed to be a straight swap(same size upper and lower wishbone balljoints)and if you use the 12 inch 1LE discs from an 88-92 Camaro you keep the same wheel stud pattern and I think use the same wheel bearings if the spindle donor vehicle is 79 or later. 2nd gen calipers bolt straight onto the new spindles and as these only move out half an inch should still fit inside 15 inch wheels ok.
Will do some more research on this upgrade but wondered if anyone else has already done this ?
A quicker cheaper upgrade I found was to replace the standard D52 size front disc pads with D614 disc pads which as you can see from the photo use the same size metal backing plates but have a much larger surface area of braking material

Might try a set of these on my 79 to see what difference they make.
Again,has anybody else already used these on a 2nd gen or any other yank that uses the same size front disc pad ?