Just finished doing a brake job on my 04 G35x and noticed that the passenger rear caliper dust boot has a rip. Ordered a caliper rebuild kit from RockAuto to replace the boot. Unfortunately, the kit is the wrong size.

All online part sites state that the front and rear calipers have the same piston bore size: 57mm. This is not the case on my car. the rear calipers are noticeably smaller. Measured the piston and it is about 1.5" or 38mm (rough measurement at best). Does anybody have any idea what the actual bore is on the rears? Maximas and Altimas have a 35mm rear caliper bore. I am wondering if those rebuild kits would be interchangeable.

Thanks.

JD