C20 disc brake conversion help thread

[May70]

I tested a few different hoses and determined the best route was to drill out a hole on the front side of the upper control arms (how they come factory with discs) and use O'Reilly Part numbers (BH86550 / BH86551). Much happier with these than some of the others I found on the forum - zero contact and the hose isn't bending back over itself.

This thread covered the discussion on brake hose selection and re-routing.

https://67-72chevytrucks.com/vboard/...d.php?t=832601

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Obviously it is likely that if you are going to this effort of modernization you will also be looking at upgrading to power steering (if you do not already have it). I decided to abandon my power assist setup and took the square body donor PS gear, pitman arm and center link. PS gear seals were shot, after three rebuild kits with the wrong seals. Three weeks of messing around with it, I said screw it and ordered a red head gear.

Selection of the gear was based on two things:
Quick vs standard
O ring vs flare fitting style

I chose the standard ratio box with the o ring style fittings as that will be directly compatible with the ls style pump fittings. Read head gear PN#2856 (3 Turn): 1980-1991 Chevrolet gear.

More info on gear/ratio selection here:
https://67-72chevytrucks.com/vboard/...d.php?t=836032 (Ratio thoughts)
https://67-72chevytrucks.com/vboard/...d.php?t=833856 (Rebuild kit mismatch issue)

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If you are installing a power steering unit onto a 1967 frame, those frames do not have a dimple which compensates for the power gears more obtruding size. Therefore you either have to dimple the frame or offset the gear. Offset is arguably minimum (less than 1/4 inch) and I had already finished painting my frame so I opted for for the spacers. Grumpy did caution the implications, which some may consider acceptable. Geometry is offset, which leaves one direction of turn less aggressive. As long as you have a good front end guy I don't see this being an issue. I have tested this and I am not worried about it.

Core support bracket will also have to be slightly trimmed.

More info here:
https://67-72chevytrucks.com/vboard/...d.php?t=836267

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Pitman arm is a Moog K6143

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Correction to this-
"Special note:
Factory 15" steel wheels will fit over the rotors but you cannot install the calipers until you get larger wheels."

I had read that somewhere and just believed it (mis-information). My stock 15" wheels have no issue with calipers bolted on.



Hope this helps.