87 GN - 4 Wheel disc????

nope. several conversions are available but so far as I recall never saw one from factory with that feature.
Must be another rare option aside twin turbos and a 5 speed manual.

Really I'd like to know if it's even possible to make the 4 wheel disc set up work with the powermaster......?
The powermaster works just fine with 4 wheel disk brakes, it's got lots of oopmh when the system is working properly. :smile: ;)

I don't believe they changed anything down at the brake hardware locations between the vacuum and powermaster systems available in 1987 on Regals.

Not sure about the hardware with the hydroboost vs. vacuum parts available in the older cars, probably nothing changed at the wheels either.