1970 front disc brake conversion

[picklito]

It's time to do the front swap to discs. It's a 70 GMC big block 2wd 6-lug with power drums. Want to keep the 6-lug and stock height. I'm finding MANY shops selling kits and parts, and the Brothers kit is currently on sale. Does anybody know how large the discs are in the various kits? I'm seeing 12" from McGaughy's. How large are the Brothers, CPP, POL, ECE, etc? How large is a stock GM setup for comparison?

I don't want to go with one of the "big brake" kits, I just want a sufficient size "OE" style replacement.

Any "must avoid" kits out there?

Thanks!

[70 shorty]

I'm interested in "OE style replacement" disc conversions too, but with a dropped spindle. I"ll be keeping an eye out here. I want OE style bc I like my stock 6 lug truck rally wheels.

[picklito]

Yes, I just bought new tires for my 15" rallye wheels! Would like to keep them.

[ksbrktracer]

Mcgaughys does a stock height or drop spindle for the 63-70 with a stock size (12") rotor. they also do a 13" rotor kit. I can get them in 5-lug or 6-lug in 12" or 13" . I can also get a 12" 6-lug rotor to fit the 71 and newer spindle with 1.25 rotor.

[hugger6933]

I am also wanting to go to disc on the front of one of my 70's [the other is gonna be 5 lug] and already have the stuff to do the swap where the use of the 88-98 C2500LD spindle ,rotor and caliper and be used. I haven't given any thought to weather or not my 15 inch rallys would fit it. I'd better give that a try before going much farther in that direction. Thanks for bringing that to light for me guys. Jim

[mmiddle]

Ridetech 11349300 spindles 2" drop. See Rob at NoLimits
1992 LD 3/4 ton rotors (6 lug) and calipers/pads.
1973-87 1/2 ton ball joints and outer tie rods.
1972 bearings and seals
This will give you 11.6" rotors

Doing this will give you replacement peace of mind should you ever need to replace the rotors or calipers.

[mmiddle]

Originally Posted by hugger6933

I am also wanting to go to disc on the front of one of my 70's [the other is gonna be 5 lug] and already have the stuff to do the swap where the use of the 88-98 C2500LD spindle ,rotor and caliper and be used. I haven't given any thought to weather or not my 15 inch rallys would fit it. I'd better give that a try before going much farther in that direction. Thanks for bringing that to light for me guys. Jim

The only issue you might run into is the original steel wheels are made for
1/2" or 7/16" stud and the 1988-9* 3/4 ton rotors are 9/16" stud. Therefore you likely will need to drill out the lug holes by 1/16".