Upgrading from kelsey hayes to???

Kennkenniff said
295s in the back is awesome I thought the biggest was 275, ive started the process of moving the wheelhouses into the frame rails, my car strangely came with the springs relocated but not the mini tubs, thanks for the Info my friend.

275's on a Duster/Demon is the most you'll do without moving the springs over at least a 1/2". I run 295's on my Duster, but that took a 1/2" spring offset and another 1/2" trimmed off the quarter lips to keep them from rubbing.

Without the mini-tubs the 3" relocation doesn't buy you any more than a 1/2" offset, so if you've got a 3" relocation and stock tubs you could likely run 295's as well as long as the backspace was right.

Kennkenniff said
My hope was by using the stock K/H disks i wouldn't have to worry to much about wheel selection, I know some late model buicks/cadillacs came with brembo calipers on all 4 wheels so im going to have to do some research on all this stuff and see if its worth doing, my car currently has centerline skinnies on the front and I dont see them staying, theres a guy locally that's started making custom sized rims to accommodate chevy poverty caps/dog dish and ive heard he has made a couple sets of mopar rims aswell

This I don't understand. You want to run Viper calipers on stock SBP rotors with SBP wheels? The Viper calipers are huge, the odds of them clearing a stock rim is about nil even if you use factory rotor. Which you can't. The Viper calipers use a 1.25" thick caliper. And there's no kit available that I'm aware of that puts them on anything smaller than a 13" rotor. A 13" BBP rotor, I might add, because you'll need at least 17" wheels to clear them.

If you want to keep your stock wheels, then I would just rebuild the calipers. The KH calipers are actually pretty decent for braking power, even if they do have some seal/leak issues.

If you want Viper calipers, you need to change a lot more than just the calipers to make it work. Even if you make your own caliper brackets I think you'll have issues with those gigantic Viper calipers clearing anything resembling a factory wheel.