68 C20 8lug disc brakes - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**slomotion** · 03-03-2010, 08:26 PM

I've been studying 1964C10's thread on disc brake conversions, and appreciate the amount of effort that went into putting that together!

Being a little on the "numb" side, I still don't know if I can accomplish what I'd like to. My 68 C20 8 lug has drum brakes all around. I know swapping out a 71/72 crossmember is the ideal method of gaining disc brakes up front, but is it possible to retain my current upper/lower control arms, and just change the ball joints and spindles from a later C20? Would this change the steering geometry significantly?
I want to retain the 8 lug configuration, and the stock ride height.
Is there an easier way then the "transplant"?

Tx Firefighter · 03-03-2010, 09:05 PM

Yes, you can absolutely put later model ball joints into your existing control arms. You'll need the spindles and brake parts as well as the steering linkage, side to side, including the tie rods and center link.

**slomotion** · 03-04-2010, 08:05 AM

Cool! Thanks Tx! Is there a block of years that is preferred for this swap?

Tx Firefighter · 03-04-2010, 08:19 AM

Whatever year from 71-87 that you come across is fine. There is no compelling reason to seek out any particular year donor.

Get the spindles and brakes, both tie rods and the center link. Refurbish as needed and install it all with new later model ball joints.

I always get the master cylinder (for a core), prop valve and brake lines too. The entire brake line system for the later trucks will bolt into your truck and you can use the nicely bent factory hard lines for a great look.

**slomotion** · 03-04-2010, 08:52 AM

Great! I already have a new MC, Prop Valve, Booster, and associated lines coming from "Pickmup" (Frank) on the "left coast".

Thanks again,
Tim

**N2TRUX** · 03-04-2010, 09:15 AM

Tim- Would you mind taking pics and documenting the conversion? It sure would make a nice FAQ.

**slomotion** · 03-04-2010, 11:13 AM

N2TRUX, sure, I'd be happy to, and some narrative as well, although I probably won't be able to submit it right away if that's OK. I'm gathering all of the parts together, but I have a couple of house projects I need to get out of the way before I can "play".

Burb · 03-04-2010, 12:21 PM

Are ya planning on doing a rear brake conversion ??

Or are ya sticking to the Drums ??

____________

Rick

**slomotion** · 03-04-2010, 12:55 PM

Hey Burb, I'd like to do the rears too, but the truck is a dually and I have no idea what that would involve. For the time being, I'm planning on disc/drums. If I find the rear would also be a relatively straight forward change, then I may if I can find the parts.
Right now the truck just has standard no-assist brakes, ( the original Flintstone set up ) and I'm thinking the power assist will help alot, then when I put discs on the front I may decide that they're enough.

Burb · 03-04-2010, 04:36 PM

Now that would be a nice project ...

hmmmm ... a dual disc brake conversion ...

___________
Rick

*RUSHNBOBO* · 09-11-2010, 03:35 PM

Quote:

Originally Posted by slomotion

I've been studying 1964C10's thread on disc brake conversions, and appreciate the amount of effort that went into putting that together!

Being a little on the "numb" side, I still don't know if I can accomplish what I'd like to. My 68 C20 8 lug has drum brakes all around. I know swapping out a 71/72 crossmember is the ideal method of gaining disc brakes up front, but is it possible to retain my current upper/lower control arms, and just change the ball joints and spindles from a later C20? Would this change the steering geometry significantly?
I want to retain the 8 lug configuration, and the stock ride height.
Is there an easier way then the "transplant"?

All u need to do is swap to '73-'87 ball joints and spindles with disc brakes.

Every thing bolts right up...except for the tie rod end which u can adapt to the larger ends with a kit from CPP.

Note the only difference between the 63-70 ball joints and 71 up is the tapered stud (its larger) the rest is the same ....use your original control arms.

Btw: the C20 and C30 67-72 front suspension is almost exactly the the same except for the hub extension for the positive offset dually wheel
...................good luck...........Dan.........................

**slomotion** · 09-12-2010, 12:44 PM

Thank you Dan.

I like your truck! Seems like there's more and more of us....

Tim

coryrob · 03-30-2017, 09:53 AM

Hello Everyone, I have a 68 C20 8 Lug I am finally getting around to restoring. I would really like to convert the truck to disc brakes all around. I have read the thread and was curious if anyone has insight on which would be the better route. Finding a complete cross member at a salvage and bolting it up or replacing the necessary pieces ball joint, spindle, etc.? I spoke to a resource at a salvage yard and he did a look up on a spindle and that reaches into 91 year. Can I use 91 parts to convert as well? Sorry to ask questions that probably been answered but I want to make sure I do this right.

03-03-2010, 08:26 PM	#1
slomotion Old Duffer Join Date: Mar 2003 Location: Maine Posts: 1,822	68 C20 8lug disc brakes I've been studying 1964C10's thread on disc brake conversions, and appreciate the amount of effort that went into putting that together! Being a little on the "numb" side, I still don't know if I can accomplish what I'd like to. My 68 C20 8 lug has drum brakes all around. I know swapping out a 71/72 crossmember is the ideal method of gaining disc brakes up front, but is it possible to retain my current upper/lower control arms, and just change the ball joints and spindles from a later C20? Would this change the steering geometry significantly? I want to retain the 8 lug configuration, and the stock ride height. Is there an easier way then the "transplant"? __________________ '68 Short C20 Flatbed Dually w/ 292 4bbl, Langdon cast headers, and WC T5 trans. '81 G10 Shorty Van "Good judgement comes from experience, and a lot of that comes from bad judgement." Will Rogers "Under promise, then over achieve."

03-03-2010, 09:05 PM	#2
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: 68 C20 8lug disc brakes Yes, you can absolutely put later model ball joints into your existing control arms. You'll need the spindles and brake parts as well as the steering linkage, side to side, including the tie rods and center link. __________________ I'm on the Instagram- @Gearhead_Kevin

03-04-2010, 08:05 AM	#3
slomotion Old Duffer Join Date: Mar 2003 Location: Maine Posts: 1,822	Re: 68 C20 8lug disc brakes Cool! Thanks Tx! Is there a block of years that is preferred for this swap? __________________ '68 Short C20 Flatbed Dually w/ 292 4bbl, Langdon cast headers, and WC T5 trans. '81 G10 Shorty Van "Good judgement comes from experience, and a lot of that comes from bad judgement." Will Rogers "Under promise, then over achieve."

03-04-2010, 08:19 AM	#4
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: 68 C20 8lug disc brakes Whatever year from 71-87 that you come across is fine. There is no compelling reason to seek out any particular year donor. Get the spindles and brakes, both tie rods and the center link. Refurbish as needed and install it all with new later model ball joints. I always get the master cylinder (for a core), prop valve and brake lines too. The entire brake line system for the later trucks will bolt into your truck and you can use the nicely bent factory hard lines for a great look. __________________ I'm on the Instagram- @Gearhead_Kevin

03-04-2010, 08:52 AM	#5
slomotion Old Duffer Join Date: Mar 2003 Location: Maine Posts: 1,822	Re: 68 C20 8lug disc brakes Great! I already have a new MC, Prop Valve, Booster, and associated lines coming from "Pickmup" (Frank) on the "left coast". Thanks again, Tim __________________ '68 Short C20 Flatbed Dually w/ 292 4bbl, Langdon cast headers, and WC T5 trans. '81 G10 Shorty Van "Good judgement comes from experience, and a lot of that comes from bad judgement." Will Rogers "Under promise, then over achieve."

03-04-2010, 09:15 AM	#6
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Re: 68 C20 8lug disc brakes Tim- Would you mind taking pics and documenting the conversion? It sure would make a nice FAQ. __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

03-04-2010, 11:13 AM	#7
slomotion Old Duffer Join Date: Mar 2003 Location: Maine Posts: 1,822	Re: 68 C20 8lug disc brakes N2TRUX, sure, I'd be happy to, and some narrative as well, although I probably won't be able to submit it right away if that's OK. I'm gathering all of the parts together, but I have a couple of house projects I need to get out of the way before I can "play". __________________ '68 Short C20 Flatbed Dually w/ 292 4bbl, Langdon cast headers, and WC T5 trans. '81 G10 Shorty Van "Good judgement comes from experience, and a lot of that comes from bad judgement." Will Rogers "Under promise, then over achieve."

03-04-2010, 12:21 PM	#8
Burb Coordinator of Synchronicity Join Date: Dec 2005 Location: West of Houston, TX Posts: 437	Re: 68 C20 8lug disc brakes Are ya planning on doing a rear brake conversion ?? Or are ya sticking to the Drums ?? ____________ Rick __________________ Rick 1971 Suburban ... W.I.P. *Build Thread* Customization is ones personal touch-- not what other people think it should be Last edited by Burb; 03-04-2010 at 12:21 PM. Reason: Sign

03-04-2010, 12:55 PM	#9
slomotion Old Duffer Join Date: Mar 2003 Location: Maine Posts: 1,822	Re: 68 C20 8lug disc brakes Hey Burb, I'd like to do the rears too, but the truck is a dually and I have no idea what that would involve. For the time being, I'm planning on disc/drums. If I find the rear would also be a relatively straight forward change, then I may if I can find the parts. Right now the truck just has standard no-assist brakes, ( the original Flintstone set up ) and I'm thinking the power assist will help alot, then when I put discs on the front I may decide that they're enough. __________________ '68 Short C20 Flatbed Dually w/ 292 4bbl, Langdon cast headers, and WC T5 trans. '81 G10 Shorty Van "Good judgement comes from experience, and a lot of that comes from bad judgement." Will Rogers "Under promise, then over achieve."

03-04-2010, 04:36 PM	#10
Burb Coordinator of Synchronicity Join Date: Dec 2005 Location: West of Houston, TX Posts: 437	Re: 68 C20 8lug disc brakes Now that would be a nice project ... hmmmm ... a dual disc brake conversion ... ___________ Rick __________________ Rick 1971 Suburban ... W.I.P. *Build Thread* Customization is ones personal touch-- not what other people think it should be Last edited by Burb; 03-04-2010 at 04:38 PM.

09-12-2010, 12:44 PM	#12
slomotion Old Duffer Join Date: Mar 2003 Location: Maine Posts: 1,822	Re: 68 C20 8lug disc brakes Thank you Dan. I like your truck! Seems like there's more and more of us.... Tim __________________ '68 Short C20 Flatbed Dually w/ 292 4bbl, Langdon cast headers, and WC T5 trans. '81 G10 Shorty Van "Good judgement comes from experience, and a lot of that comes from bad judgement." Will Rogers "Under promise, then over achieve."

03-30-2017, 09:53 AM	#13
coryrob Registered User Join Date: Mar 2013 Location: The Colony, TX Posts: 1	Re: 68 C20 8lug disc brakes Hello Everyone, I have a 68 C20 8 Lug I am finally getting around to restoring. I would really like to convert the truck to disc brakes all around. I have read the thread and was curious if anyone has insight on which would be the better route. Finding a complete cross member at a salvage and bolting it up or replacing the necessary pieces ball joint, spindle, etc.? I spoke to a resource at a salvage yard and he did a look up on a spindle and that reaches into 91 year. Can I use 91 parts to convert as well? Sorry to ask questions that probably been answered but I want to make sure I do this right.



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