Thread: Rear Brake Question

My friend's driver's side rear caliper froze on him. What I'm wondering is - would a P10 or P11 rear caliper fit on our cars? We were gonna go get a junkyard caliper (just to be a bit cheaper), but B14s tend to be scarce locally. Does anyone know if a G20 caliper would fit, or is it just a totally different setup and I'm wasting my time asking?