More info about the front kit:

The front GM F, X Body disc brake kit allows an easy solution to convert your drums to disc. Everything included in one kit. The spindles are stock height and will not change the ride height. Your rims need to be 15" or larger or the kit will have clearance issues that you'd have to work around. Disc brake conversions typically create an offsets of 1/4" to 3/8"

About the Wilwood Calipers:

Wilwood#120-10937-RD

D52 Dual Piston Caliper

2" Diameter Pistons

1.28" Rotor Width

Wilwood's D52 caliper is a direct bolt-on 2 piston replacement for the factory original single calipers on many 1968-96 GM Passenger Vehicles and Trucks. Forged billet aluminum bodies, stainless steel pistons, and competition style high-temperature seals put and end to the rust, bore pitting, and seal failures that plague the OE caliper design. D52 brake calipers provide low-maintenance performance and a huge weight savings with high temperature reliability for the street and track.

D52 performance brake calipers mount in the stock location over stock rotors, use the original style OE D52 brake pads and an OE banjo bolt brake line. mounting. Calipers can be used with most wheels that clear the OE calipers. The Rear calipers with 1.25" piston provide 2.46 cubic inches of piston area per caliper, to maintain the original front to rear brake bias and use of the OE master cylinder.

More info on the Rear Kit

• Does not fit MOSER Rear Ends

• Works on C-Clip rear ends.

• Each rotor is drilled for GM 5 x 4.75'' w/ 7/16'' stud bolt patterns.
  
  
• Maximum diameter of 6.11" to fit rotor hat. .050x45 Degree Chamfer. 2.786" max register axle.
  
  
• Fits 15" or larger rims
  
  
• Double check the ends of your axle before ordering. Some 10/12 rear ends will have to modify the axle or rotor opening to get the rotor to fit.
  
  
• You are receiving two right (Driver) side rear calipers in this kit. This is so one caliper can face forward and one backwards for staggered shocks.