Sorry I used the wrong picture for an illustration, the wheel sizes are dictated by the diameter of the rotor...here is the specs on the serious street setup just for reference.
I'm sure talking to any of these companies on the phone should be able to get your setup sorted out....
SERIOUS STREET/SERIOUS STREET-PLUS
(1-piece 11" dia. / PBR 2-piston PGC)
The Baer Claw® SERIOUS STREET brake system is designed to fit within the smaller period-correct wheels popular on 60's and 70's muscle cars, such as '67 to '72 A-bodies and '67 to '69 F-bodies (as well as selected X-body applications). Featuring 2-piston aluminum calipers and 1-piece, 11" cross-drilled, slotted and zinc-washed rotors, they jazz up the looks of these older street machines while delivering the much needed braking performance of today's technology. SERIOUS STREET brake systems fit within virtually all 15" wheels (occasionally a spacer is required).
Essentially the same as the SERIOUS STREET, the SERIOUS STREET-PLUS brake system employs 2-piece rotors for overall weight reduction, enhanced performance, and a dynamic, race-car look.
Rear systems for both versions are available with 11.350" dia. rotors and PBR 1-piston calipers with park mechanism (not shown).