PontiacBonnevilleClub.com

Since the Seville doesn't have the greatest brakes (or handling for that matter) I was thinking of an upgrade. Was cleaning out some storage left overs and found the Bonnie GXP stuff I have laying around. Set of 4 calipers and rotors. So I thought, why not put these on the Cadillac?

I guess I could just pop the wheels off and try them but I've been so busy lately I barely have time to wash her. So I cross-checked the parts numbers. It looks like the rear calipers are the same part number for 2002 SLS, 2002 SSEi, and 2004 GXP so I guess I would just leave those well enough alone.

But the fronts: The SLS and the SSEi share the same rotor. BUT the part numbers are different for the calipers.

Bonneville Caliper
http://shop.advanceautoparts.com/p/rema ... rm=caliper#

Cadillac Caliper
http://shop.advanceautoparts.com/p/rema ... rm=caliper#

GXP Caliper
http://shop.advanceautoparts.com/p/rema ... rm=caliper

They look like dang near the same thing. So I assume the GXP front dual piston one should bolt right up on the Caddy. Hate to get rid of brand new brakes though, that are on there

GXP wheels may follow....(Edit: After thought, I would have to use the GXP wheels as my factory 16's wouldn't fit over the brakes)

Any thoughts?

The Rear GXP brakes and sls/sts of that generation are the same. The GXP frotn calipers should bolt up no problem to the STS as long as you have the Bonneville GXP brake hoses and rotors. You will also need 17" rims

^Yes. Would need a ridiculous offset to fit 16s over the GXP brakes.

Hence my reasoning for NEEDING GXP wheels and new tires to fit on the Cadillac

If I do go this route, should I stick with stock GXP tire size?

Yes