[Captainfab]

Regarding the different calipers.

The Wilwood D52 calipers are a dual piston direct replacement/upgrade for the OEM D52 caliper applications. The specifics are as aggie91 posted. The "D52" just refers to a particular size of caliper that GM used from the late 60's when disc brakes came out thru about 1978-79 in the passenger cars. these come in two different piston diameters, 2.938" (2 15/16") and 3.156" (3 5/32"), but in the same casting with mounting pin dimension of 7.06". These were used in truck based applications up thru 1987 and thru 1991 in the Suburbans and Blazers in both 2wd and 4wd.

In 1978-79 on the passenger cars (there seens to be some cross overs there with different models too) GM went to a smaller casting for the calipers commonly referred to as "The Metric Caliper" There could be a "D" designation for these as well, but I don't know what that is off hand......I'm still learnin too. These calipers were used thru around 1994? when the PBR style caliper was used.

Enough of caliper class for now.....I made some progress on plan 'B' of the Astro rotor bracket. Here are some pics where I left off today. Keep in mind this is just a prototype, so the finished product will be more refined and nicer. Tomorrow I will be working on finding the most cost effective way to make the one part. So by Wednesday I should have some pricing on this rotor and caliper bracket setup. As a side note I noticed that the new slide pins supplied with the reman calipers seem to have a metric sized hex in them. My 3/8" allen didn't want to fit and I didn't have the correct metric sized allen to fit. It would appear to be a 9mm.....don't know if there is such a size?