Disc Brake Upgrade Reference Thread

[Intimudator]

Originally Posted by aggie91

Intimudator - First off, welcome to the forum. I think you will find this site to be very helpful.

It basically comes down to the ball joints and tie rods...

I am not versed in the 60-62 torsion bar front suspension, so here is what you need to look at: If the ball joints are changed to the '85 1 ton ball joints, then yes the spindle will bolt up...NOW, will the ball joints actually fit the control arms for your '61 C30? I don't know that. I would check the OD of the lower '85 BJ against the OD of the lower '61 BJ, if they are the same size, then yes it should press into the arm. I believe the upper control arms use a bolt in style, if the '61 is the same as what was in my '65, than the upper BJ is a direct bolt in for the '85 upper BJ.

As for swapping the arms themselves, the lower want work because of the torsion bar from suspension under your '61.

Now, the tie rods, this can be solved by using an adapter sleeve if the thread sizes are different between the years like the C10's are.

Good luck, let us know what you decide to do and how it works out!

Thank you for the fast response. I was hoping to hear some one has actually done it but I will go measure them and go from there, I'll keep everyone posted so everyone on here will know for sure if it can be done
Posted via Mobile Device

[Captainfab]

I have seen a couple '60-'62 C 30's that had coil springs in the front. If yours does have coil springs, you should be able to change the balljoints and bolt on the '85 spindles. If you have a torsion bar front suspension, that will not work. You will have to change the entire front suspension including the crossmember.

[Intimudator]

Originally Posted by Captainfab

I have seen a couple '60-'62 C 30's that had coil springs in the front. If yours does have coil springs, you should be able to change the balljoints and bolt on the '85 spindles. If you have a torsion bar front suspension, that will not work. You will have to change the entire front suspension including the crossmember.

I have torsion bars. Could I modify the control arms(weld) ball joints to fit or they completely different? Will the complete suspension bolt in without cutting up the truck where it could never be taken back to stock or just drilling holes?
Posted via Mobile Device

[Captainfab]

It would take a lot of fab work to install the '85 lower ball joints. I would just change the entire suspension. It is no different than on a '60-'62 C10 or C20. Mainly just a bunch of holes to drill. If you had a '63-'66 it would only be one hole on each side to drill and one to elongate on each side.

Originally Posted by Intimudator

I have torsion bars. Could I modify the control arms(weld) ball joints to fit or they completely different? Will the complete suspension bolt in without cutting up the truck where it could never be taken back to stock or just drilling holes?
Posted via Mobile Device

[64RC20]

Hello Everyone...

I just became a registered user today. Hooray!

I want to take this opportunity to express my thanks and gratitude for everyone who has ever posted here, not just on this thread, but everywhere in this forum. You folks really make this a better world, for sure!

[64RC20]

And now it's crunch time!

I've got a mostly stock '64 C20, with its original front brakes and single chamber master cylinder. And way back in 1982, I had a great shop down in Los Angeles swap out my original 4.55/1 stock rear end to a '76 (if memory serves) C20 14 bolt rear end, and I had that upgraded to a 3.21 ring and pinion. (My 80 mile/day commute was killing me on gas and this swap jumped me up from 10.5ish mpg to 14.5ish mpg!). Hooray!

It's finally time for brakes again and I intend, at minimum, to split the front and rear brakes and convert to a dual chamber M/C. But converting to discs is something I never thought practical...until I found this forum. Now that I've read through every single post in this thread (all 21 pages worth!) plus several other related posts, I now know it is eminently doable. But one key point has eluded me. It's similar to MATERI1's question from a few posts back..

I am also not sure of what a 73-87 C20 front suspension swap will require with regard to my manual steering box, which I also want to keep. I have just found a '79 C20 donor truck where I can get the entire front suspension: crossmember, steering, brakes, etc, for $200 (haven't seen it yet, though). But I don't know whether my old pitman arm will bolt up to it. Or can I use the donor truck's pitman arm on my old manual steering box (not likely, per Captainfab...but mine's a '64 C20...is there hope!)? Or...can I bolt up a '79 C20 manual steering box without any modifications? (Autozone has them...sigh!)

[Captainfab]

No you can not use a '73+ power steering pitman arm on your '64 manual steering box. If you are planning on using the '79 steering linkage( which I recommend) you can use the '79 manual steering box. However I think you will still need a steering box adapter plate. It's been so long since I have seen a '73+ manual steering box I don't remember if it also needs the dimple in the frame for clearance.

Are you staying with manual brakes too?

[64RC20]

No, if I can accomplish this disc upgrade, I'll definitely want a booster/MC and proportining valve. And with my Social Security budget, I'm open to suggestions on those parts...I found a combo package at Classic Parts but it's over $300 and though it looks nice, I'm hoping to find a less expensive alternative!

My previous engine spun a cam bearing and died (a used 350...lasted 29 years, God bless it) right after I invested $1200 on nice new wheels and tires, so I wanted to protect that $1200 investment. Got lucky on another used 350 from PicknPull ($150 out the door, plus another $100 or so in timing chain, gaskets, etc.). Got lucky there...perfect compression and it runs like a Swiss watch! But now my brakes are wanting attention. So now I'm trying to get them done, including splitting front from rear, as cheaply and safely as possible. When I found this forum, I realized disc brakes were doable.

(If my next posts looks weird, it's because I'm gonna try to use the "quote message in reply" function. That's another learning curve where I'm still looking way up!)

[Captainfab]

With one of my booster brackets you can use a readily available booster and master from a wrecking yard, and have it mounted correctly and safely for a bit less than $300.

Originally Posted by 64RC20

No, if I can accomplish this disc upgrade, I'll definitely want a booster/MC and proportining valve. And with my Social Security budget, I'm open to suggestions on those parts...I found a combo package at Classic Parts but it's over $300 and though it looks nice, I'm hoping to find a less expensive alternative!

My previous engine spun a cam bearing and died (a used 350...lasted 29 years, God bless it) right after I invested $1200 on nice new wheels and tires, so I wanted to protect that $1200 investment. Got lucky on another used 350 from PicknPull ($150 out the door, plus another $100 or so in timing chain, gaskets, etc.). Got lucky there...perfect compression and it runs like a Swiss watch! But now my brakes are wanting attention. So now I'm trying to get them done, including splitting front from rear, as cheaply and safely as possible. When I found this forum, I realized disc brakes were doable.

(If my next posts looks weird, it's because I'm gonna try to use the "quote message in reply" function. That's another learning curve where I'm still looking way up!)

[64RC20]

The first thread I found on this subject was from Hilandr451, for his totally awesome project on his '66 C20:

http://www.67-72chevytrucks.com/vboa...d.php?t=357610

He upgraded to power steering, which I decided to forgo, based on the expected cost (and I'm scared to death to cut my steering shaft!). I would reconsider this if power steering proves easier and cheaper. But in an effort to find a way to save my original steering, and figure out all the "gotcha's" concerning a C20 disc swap as opposed to a C10, I read through all 21 pages of this current thread looking for every reference to a C20. The list below includes every such post I found:
.
36-39, 48-50, 55-56, 89-90, 155-160!!!, 165-171, 189!, 216-(217!)-219, 293, 336-337, 378, 384-385, 515!-516!, 519!-520!

[64RC20]

Hmmm...the "Quote message in reply?" check box is not working for me. So please bear with me....

In post 216, user 65ChevyC20 asked this:

My question is should I do the complete crossmember swap or should I swap the various pieces over to the crossmember on my 65. Which would be easier is what I am asking.

And Captainfab, you replied:

Well from a easier perspective, just switching the ball joints, spindles, rotors, calipers, etc. would be the easiest. The '79 lower control arms will not bolt up to your '65's crossmember, since there are no saddles there..

There was no mention of the tie rods, so I guess I'd better ask about them. I'll have my old ones and the new ones from the donor truck so hopefully I'm covered. So, will tie rods, or anything else, be a problem with this "easiest" option? And this option lets me keep my stock manual steering box, right?

From a durability/parts availability perspective, swapping in all of the donor truck's suspension (with or without the crossmember) would definitely be wise, too. But then I think I would have to locate the donor truck's idler arm on the frame and drill new holes for it, right? (I think I could handle that). And then I'm still up against a new 73-79 (to avoid metric) steering box. Can I get it in without cutting my steering shaft? Maybe with your adapter?

[Captainfab]

I can not verify that the disc brake lower ball joints will press into the '63-'66 C20 lower control arms. Until someone verifies that, I continue to recommend just changing the entire front suspension, crossmember and all.

Yes you will have to drill new holes for the later model idler arm. When converting to power steering you must shorten the original steering column shaft. There's no way around it.

Originally Posted by 64RC20

Hmmm...the "Quote message in reply?" check box is not working for me. So please bear with me....

In post 216, user 65ChevyC20 asked this:

And Captainfab, you replied:

There was no mention of the tie rods, so I guess I'd better ask about them. I'll have my old ones and the new ones from the donor truck so hopefully I'm covered. So, will tie rods, or anything else, be a problem with this "easiest" option? And this option lets me keep my stock manual steering box, right?

From a durability/parts availability perspective, swapping in all of the donor truck's suspension (with or without the crossmember) would definitely be wise, too. But then I think I would have to locate the donor truck's idler arm on the frame and drill new holes for it, right? (I think I could handle that). And then I'm still up against a new 73-79 (to avoid metric) steering box. Can I get it in without cutting my steering shaft? Maybe with your adapter?

[Thommyknocker]

Hi guys,
One thing I didn't find while I was researching the crossmember swap was a good picture of the hole modifications needed.

This is the template I made to transfer the hole pattern.
We are putting a 71 crossmember under my son's 61 C10

I hope these pictures help someone else.
TJ

[68ihscout]

I was reading through this whole thread ,unless i missed it i couldnt find any info on 1970 c20 8lug disk conversion ,i found a donor 73/87 crossmember and all should bolt right up ,i have power assist drums now ,do i need a new booster and brake lines ?? Thanks in advance (or ahould i ask what all do i need )
Posted via Mobile Device

[Captainfab]

Yes a '73-'87 C20 front suspension crossmember will bolt up just like a '73-'87 C10 crossmember will. In fact on the '67-'72 C20/30's, you do not have to change the entire crossmember like you do on the '63-'66 C20/30's. You can change just the spindles. I believe the '73-'87 lower balljoints should press into the '67-'72 lower control arms. Yes you will need to change the master cylinder and add a proportioning valve. I do not know of a disc/drum master cylinder that has the deep bore in the back of the piston, so you will likely need to change the booster also.

Originally Posted by 68ihscout

I was reading through this whole thread ,unless i missed it i couldnt find any info on 1970 c20 8lug disk conversion ,i found a donor 73/87 crossmember and all should bolt right up ,i have power assist drums now ,do i need a new booster and brake lines ?? Thanks in advance (or ahould i ask what all do i need )
Posted via Mobile Device

[68ihscout]

Originally Posted by Captainfab

Yes a '73-'87 C20 front suspension crossmember will bolt up just like a '73-'87 C10 crossmember will. In fact on the '67-'72 C20/30's, you do not have to change the entire crossmember like you do on the '63-'66 C20/30's. You can change just the spindles. I believe the '73-'87 lower balljoints should press into the '67-'72 lower control arms. Yes you will need to change the master cylinder and add a proportioning valve. I do not know of a disc/drum master cylinder that has the deep bore in the back of the piston, so you will likely need to change the booster also.

Thank you Captain for that great info , any recomendations on what booster to use ,or does 73/87 work?
Posted via Mobile Device

[Captainfab]

Many people insist on using the '73-'87 boosters, but you have to drill holes to mount it and it is not exactly mounted correctly. My booster brackets use all available factory attachment pints and securely attaches the booster/master to the pedal bracket as GM designed. There are many, many, many compatible boosters. In addition to those mentioned in the for sale thread, every booster bracket comes with a list of compatible boosters including a few part numbers.

Originally Posted by 68ihscout

Thank you Captain for that great info , any recomendations on what booster to use ,or does 73/87 work?
Posted via Mobile Device

[Clyde65]

Roll the cross member out and roll the disc brake one in, 14 bolts, 4 you will need to drill.

[Chevy Fleetside]

Check Craigslist. You might be able to pick up a whole truck for a few bucks. Sell the rest off for parts. That is if you have the room for that. I did that with two trucks and scraped what I didn't sell or use.

[66_C20]

Originally Posted by Chevy Fleetside

Check Craigslist. You might be able to pick up a whole truck for a few bucks. Sell the rest off for parts. That is if you have the room for that. I did that with two trucks and scraped what I didn't sell or use.

Yeah that’s what I’ve been going back and forth with lately, whether to snag the full crossmember assembly from a junkyard or buying a truck off craigslist, snagging the crossmember assembly off of it and then scrapping the rest. I just don’t want to end up upside down money wise and I’m not quite sure what a fair price of the crossmember assembly would be versus what I could get for a scrapped square body.

[Chevy Fleetside]

Originally Posted by 66_C20

Yeah that’s what I’ve been going back and forth with lately, whether to snag the full crossmember assembly from a junkyard or buying a truck off craigslist, snagging the crossmember assembly off of it and then scrapping the rest. I just don’t want to end up upside down money wise and I’m not quite sure what a fair price of the crossmember assembly would be versus what I could get for a scrapped square body.

I think up to $200 is a fair price but also you will probably want to rebuild it.

[66_C20]

Originally Posted by Chevy Fleetside

I think up to $200 is a fair price but also you will probably want to rebuild it.

I would absolutely rebuild it with all new bushing and whatnot before swapping it over. I found this, it’s about an hour and a half away from me, guy says it’s a 73-87 but doesn’t know the exact year and wants $250 for it.

[Chevy Fleetside]

If you go for it offer him $150 because of all the rust. He might come back with $200 but bring the whole $250. Just mention how the bushings are all cracked and need to be replaced.

[Captainfab]

Years ago I used to sell C10 front suspensions for $150. I can't sell a C20 suspension around here. I just end up taking them to the scrap yard.

Since it does have the steering box, entire steering linkage, sway bar and engine mounts, which are all usable on your truck, $250 isn't a bad deal. I would still try and get it for less. Also take into consideration whether the seller is willing to load it for you.

The C20's have the steel control arm bushings, not rubber as the C10's do. They do still wear though.

[66_C20]

Got him to take $200 for it. Just need to figure out how to load it and if it’ll fit in the back of my 2 door wrangler. Doing a little research, it looks like that generation of truck has a front track width of 65.8”. Which it means it just barely will fit with some finagling. I guess we’ll see.