Works with factory housing ends. 
 
Complete Rear Disc Brake Conversion Kit Includes:
11" GM Rotors Multi Pattern
Fits 5x4.75" w/ 7/16 Studs & 5x4.5" w/ 1/2 Studs 
Large GM Large Bore Single Piston Calipers w/ Self Adjusting E-Brake (1979 Cadillac El Dorado) 
D54 Pads Included
Caliper Brackets & Spacers
Bracket Hardware
Flex Hoses & Clips
Emergency Brake Cables
Tech Notes:
Maximum diameter of 6.11" to fit rotor hat.
.050x45 Degree Chamfer
2.786" max register axle
Does not Fit 14" Rims Must use 15" or larger
When installing rear disc brake kit a disc/disc proportioning valve with a 1-1/8" bore master cylinder will be needed.