Wilwood disk on the front and drum on the back is fine. It's when you try and mix two diff calipers. One is solid mounted and one slides.
master will not work from my findings. It seems the fluid to move the sliding calipers vs the solid mounted creates a volume issue.
I have 3 masters, 2 p-valves and 2 sets of rear brakes. One set the gm small caliper and now the wilwood.
Wilwood has had to replace a brand new master for me. Itwas broke right out of the box.
I have replaced brake lines and so on. If anyone can make this work please let me in on the process.