Disc Brake Upgrade Reference Thread

[ChiefRocka]

Originally Posted by Captainfab

The suspension from a '88 pickup will not bolt up to your '66. If you had gotten your parts from a '71-'87 pickup or '71-'92 Suburban, you could do as you are asking.

The complete pickup platform changed in '88, and is not interchangeable with earlier years. The only way you can use those parts on your '66 is to use your original upper control arm, a '63-'66 C20 lower control arm, and then install the '88 upper and lower balljoints, spindles, rotors, calipers, etc. This is the same as the 6 lug conversion described in this thread.

So you CAN use a '63 C-20 LCA....with an '88 BJ ?

It doesn't have to be a '67-'87 LCA ?

I have a rolling '63 C-20 Chassis that I am parting out.

[raycow]

Russ and Captain, thank you for clearing that up. It makes sense that if a factory part would fit, there wouldn't be any need for the aftermarket 6 lug rotors.

Ray

[Captainfab]

The '63-'70 C20 lower ball joints are the same part number. The '71-'87's are a different part number, but the ball joint hole in the LCA is the same size. The only issue with using a '63-'66 C20 LCA is the different shaft that they use. It is basically flat with holes for bolts to attack to the crossmember. So if you were to use the '63-'66 C20 LCA's on anything other than a '63-'66 C20 crossmember, the shafts would need to be changed to the '67-'86 C20 style.

Originally Posted by ChiefRocka

So you CAN use a '63 C-20 LCA....with an '88 BJ ?

It doesn't have to be a '67-'87 LCA ?

I have a rolling '63 C-20 Chassis that I am parting out.

[ChiefRocka]

Originally Posted by Captainfab

The '63-'70 C20 lower ball joints are the same part number. The '71-'87's are a different part number, but the ball joint hole in the LCA is the same size. The only issue with using a '63-'66 C20 LCA is the different shaft that they use. It is basically flat with holes for bolts to attack to the crossmember. So if you were to use the '63-'66 C20 LCA's on anything other than a '63-'66 C20 crossmember, the shafts would need to be changed to the '67-'86 C20 style.

So....could I just use my existing C10 crossshafts on the C20 arms ?

Or, does it have to be '67-'86 in order to bolt to my 63' c10 X-Member ?

I think I would prefer to use newer style rubber bushing style arms anyway...keeping it 6-lug

[Captainfab]

Thonly way you could use those '91 8 lug parts is if it is the Square body style. The Suburbans, and Crewcabs, ans possibly a couple other models were still the Square body thru '91. If it is the '88 and up body style, the only thing you might be able to use would be the rear differential. I'm not sure on the width of the 8 lug rear differentials of those years. I know that the 5 lug differentials are too wide to use in the older trucks. One other thing that you could use from it if it is a newer style truck, is the brake booster, master and prop valve, with one of my booster brackets. That will bolt right up to your '64 GMC.

Originally Posted by karlbenz

wow, this is a lot of info. I am confused(which usually doesn't take a whole lot) I am wanting to put 8lug on my front end of my 1/2 ton 64gmc. I have a 91 8lug truck sitting here that I can use for parts. can I use anything off it?

I have not done it, but I'm thinking that the C10 shafts and bushings would fit the C20 LCA's. But yeah if it were me I would upgrade to the '73-'87 control arms with the rubber bushings. I would also recommend upgrading to the larger LCA shaft U-bolts used in the '73-'87's.

Originally Posted by ChiefRocka

So....could I just use my existing C10 crossshafts on the C20 arms ?

Or, does it have to be '67-'86 in order to bolt to my 63' c10 X-Member ?

I think I would prefer to use newer style rubber bushing style arms anyway...keeping it 6-lug