8-lug disc brake conversion

[1970greenmachine]

Hello, all! I'm new here and looking for the 8-lug experts. I have a 1970 C-20 3/4-ton that has manual drum brakes all around (ugh). I'm looking to do an eventual 4 disc brake setup with a 14-bolt full floater rear end. I'm doing it in steps and want the front setup to start with. I got spindles, discs, and calipers from an '88 suburban in really good condition. Also picked up some new outer tie rod ends, but I heard I may need a special adapter sleeve to join my old inner tr's to these...? Also, which ball joints do I need: '88 suburban or '70 c-20? I know I'll need a proportioning valve: either aftermarket or one from a front disc/rear drum (for now) gm truck, right? Should I get other parts off the suburban (the rear is gone from it)?

Thanks

[sleepertruck72]

You would probly need all the parts off the suburban (ball joints,spindles,etc)I would suggest a 71-72 disc set-up from a C-20. Try looking in the parts for sale you may find some locally. They are easy to find and should be fairly easy to swap. Just a suggestion. Im sure someone here will tell you how to swap the burb parts though. Good luck

[airdale94]

Thge easyiest way is to just get everything like sleepertruck said. Then if you need any parts you just get them for what you got them of of. The only thing you really need off the 71-72 is the brake booster and bell cranks. You can also do the brake booster conv. in the FAQ.

[kcjones]

You guys are absolutely correct from what I've found (although I'm not absolutely certain about this): ball joints, spindle, rotor, caliper, hoses, outer tie rod all need to match each other (70 C20 gear not the same as 88 C20 gear). booster and m/c need to match each other (3/4T to 3/4T) but don't need to match the actual brake or steering components.

Inner and outer tie rod ends may match (meaning you can use the adjuster sleeve you've got on your 70) between 70 C20 and 88 C20. If not, get the 88 C20 inners and outers. The 88 inners should fit the 70 drag link. Pitman and idler need to match the truck, not the steering components (70 C20 pitman for 70 C20 steering box).

[1970greenmachine]

I did grab a '68 c10 power boster/mc setup awhile back. Is this going to create enough pressure for the 3/4 ton gear or should I get something else? I'm sure anything will be better than the manual brakes I have now...

[kwmech]

All the tie rods and ball joints and the centerlink are different between the drum and the disc set-ups. Different tapers.

[airdale94]

If your brake hoses are mounted on the rear of the cross member you can use the drum brake hoses.