Caliper Upgrade JB7 vs JB8

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ldaggerl

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I'm looking to make some updates to my brakes (new topic I know), currently I have everything to do the hydroboost swap including a new brake pedal. With this I want to upgrade my calipers as I need new rotors and pads anyways. I'm not completely understanding the difference between JB7 and JB8 calipers.

High level I know the JB7 is 3.145" (https://www.rockauto.com/en/moreinfo.php?pk=3255261&cc=1160503&pt=1704&jsn=18466) for the piston and JB8 is even bigger than that at 3.386" (https://www.rockauto.com/en/moreinfo.php?pk=2041036&cc=1161582&pt=1704&jsn=18473). I know the JB7 are 8600lb rated and JB8 being 10000lb rated.

My truck is a K2500 with 5.7L so I have the 7200lb rated brakes currently that are 6 lugs. I wanted to swap out the calipers and brake pads. I know that I can do that with the JB7 while still retaining the 6 lug rotors. I wasn't sure if I could use the JB8 calipers and pads as well or is it different?
 

Schurkey

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I suspect--but don't know for sure--that the JB8 calipers will bolt right up in place of the JB7 units.

However, you may want to look at the master cylinder bore diameter for the JB8 brakes. The bore may be larger to help fill the bigger bore of the calipers
 

ldaggerl

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That was one area I was concerned about but was trying to figure out if it was being excluded and I suppose that is why.

I'll stick with the JB7 just for simplicity and brake feel.
 
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