Disc Brake Upgrade Reference Thread

[65ChevyC20]

Originally Posted by Captainfab

. Did you get the steering box with the front suspension?

I did get the steering gear box along with all the other componentry. I want to upgrade to power steering also.

The motor is still in my 65. I may just swap the pieces over then and leave the engine in the vehicle.

One other question, since the front crossmember is out of the vehicle I can no longer use the jack stand and floor jack to release pressure one the coil spring. I don't want it to explode in my face, any suggestions besides wrapping a tie down strap around the upper and lower arms?

[Captainfab]

I've not had an issue with disassembiling a front suspension out from the truck. I just stand to the side when I hit the lower boss on the spindle to release the lower ball joint. If you're worried about it, tie a rope or a ratchet strap to the spring and to somewhere else on the suspension, to keep it in place.

[restorevival]

Full X-member vs component swap and power steering upgrade…?

First of all, thank you to everyone for the wealth of info. This is my first post, though I have been reading this forum for quite some time. I think I have this all figured out, but there are a couple points that I would like some confirmation/correction on. Can someone please review and tell me what I am missing…

My truck: ’66 GMC 1000, 305 V6

This is my daily driver, so ultimately I’m looking for the least amount of down time for the truck. A weekend would be stellar. In the end I want to have front power disc brakes and power steering, though the brake upgrade takes priority over the steering upgrade.

From reading this thread, I have gathered that a full cross member swap would be least amount of future maintenance the least amount of down time if I rebuild all necessary parts on the donor suspension (don’t have a donor yet) and bolt on some aftermarket 6 lug rotors prior to putting my truck on jack stands. What can I expect to run into with the engine in the truck? I'll likely need to drill/"stretch" some holes, what else? According to post #197 I may not even need to drill any holes… But according to posts #216-217 this is not the easiest way of swapping…

If I upgrade steering at the same time, surely there are other things to do. I have not searched the forum for steering upgrade threads yet. I have read CPP’s page on how to do it, but their instructions are based on my ’66 suspension. What do I need to grab from the donor vehicle to make the steering upgrade as complete and painless as possible? (suggested links?)

I’ve never taken on a project quite this large (on my own) but have plenty of experience otherwise. Just don’t want to get myself half way through and start kicking things in frustration…

Also, my truck has aftermarket wheels. If there is going to be a caliper clearance issue with my wheels, where would it be? What part of the wheel should I measure to see if they will work?

Necessary adapters...?:
brake booster adapter plate, power steering box adapter plate, possible brake line fitting adapters, what else?

Donor requirements…?:
1.25” rotors
’73-’87 pickup; ’73-’91 suburban

And finally: can I use a 1987 G20 Conversion Van as a donor?

Thank you in advance!

Here's the truck as it currently stands, all stock... except for the bed of course.

[krazy_texan]

so in a nutshell i can just pull the entire crossmember out of a 73-87 and bolt it in my 65 with maybe a few holes drilled, then if i want to keep the 6 lugs just order new rotors and call it good? cause that sounds like the easiest, fastest and cheapest route for me.

[Captainfab]

You can do the conversion that way if you like, but it is definitely easier without an engine in place. You will have to drill one hole on each side, and elongate one hole on each side. This is a quick and easy way to do the conversion, if rebuilding toe entire front suspension in not necessary or not in the budget currently.

The disc brake upgrade can also be done by removing everything from the donor crossmember and bolting up to your existing crossmember. The later model lower control arm shaft U-bolts are larger diameter than the early ones. I recommend drilling out your crossmember and using the larger diameter U-bolts. You can also keep your existing control arms, and just change the ball joints and add the spindles, rotors, calipers, etc.

You can use the aftermarket 6 lug rotors, as long as you have the HD spindles with the 1.250" thick rotors.

Originally Posted by krazy_texan

so in a nutshell i can just pull the entire crossmember out of a 73-87 and bolt it in my 65 with maybe a few holes drilled, then if i want to keep the 6 lugs just order new rotors and call it good? cause that sounds like the easiest, fastest and cheapest route for me.

[camaney]

suscribe

[ChiefRocka]

Well .... I started the process of sloooowly collecting parts for my conversion.

I picked up some A-arms and a center steering arm from a late 70's because I wanted rubber bushings.

I just lowered a customers '96 1500 using dropped spindles, so I now have the stock spindles as an option.

I'm thinking about reworking the lower a-arm to except the correct ball-joint.

NOTE: When looking for a-arms at a wrecking yard...find a greasy truck !!

(LOL, we found a grease free truck, surface rust, man it took all day to wrench those fasteners off...)

[slick copper]

This may have been covered already. I'm running vintage American Racing Turbine wheels (6 lug) and don't wanna give them up. If upgrading to 6 lug disc brakes will it affect my wheel backspacing? Pretty much will I be able to keep my wheels without it looking stupid? Here's a pic of my truck. Keep in mind I haven't lowered the front yet in the pic (in progress). 4 wheel drums right now.

[Captainfab]

When switching to front disc brakes, it does increase your track width some. I just don't remember exactly how much.......I wanna say 1-1/2". There is a brand of dropped spindle that is supposed to compensate for some of that, but there again I don't remember what brand. Hopefully someone that knows will chime in. Sorry I couldn't be more help.

[Slow Build]

Originally Posted by Captainfab

There is a brand of dropped spindle that is supposed to compensate for some of that, but there again I don't remember what brand. Hopefully someone that knows will chime in. Sorry I couldn't be more help.

CPP Modular spindles. They are more expensive plus you need to buy their caliper mounting kit. You can't run rear dust covers with them.

According to Justin at Scotts Hot Rods in the following thread (post #74) the CPP Old School New School spindles do the same. I haven't done any research to verify this yet. CPP doesn't show these on their website and the only place I've heard about them is through this thread.

http://67-72chevytrucks.com/vboard/s...=485760&page=3

Another thread I just found.
http://67-72chevytrucks.com/vboard/s...d.php?t=485760

[Captainfab]

THanks for posting. I was thinking it was the CPP modulars, but wasn't positive. I did not know that there were possibly other spindles that move the wheels in.

Originally Posted by Slow Build

CPP Modular spindles. They are more expensive plus you need to buy their caliper mounting kit. You can't run rear dust covers with them.

According to Justin at Scotts Hot Rods in the following thread (post #74) the CPP Old School New School spindles do the same. I haven't done any research to verify this yet. CPP doesn't show these on their website and the only place I've heard about them is through this thread.

http://67-72chevytrucks.com/vboard/s...=485760&page=3

Another thread I just found.
http://67-72chevytrucks.com/vboard/s...d.php?t=485760

[slick copper]

Thanks CaptainFab! Hopefully someone can help shed some more light on this for me. Anyone???

[slick copper]

Thanks Slow Build! Very helpful to know. So for what I'm talking about wanting to do the CPP modular spindles will be my best option. They will still push out my track width 3/4" on each side. But it's only that little bit and wayy less than other spindles. I think I can live with that, and looks like I can keep my wheels!

Couple more questions for you guys.
1. To run my 15" wheels will I need to run the 12" rotors or can I go with the 13"?
2. If I wanted to go 4 wheel discs (add discs in the rear) Would that affect wheel spacing and how much?
Thanks guys, sorry to be a bother. I'm sure all this has been covered before at some point. Just wanna get my facts straight for when I do all this.

[Captainfab]

With 15" wheels, you will have to stay with 12" rotors. If you convert the rear to discs, that will add 3/16"-1/4" to each side to the overall axle width.

Originally Posted by slick copper

Thanks Slow Build! Very helpful to know. So for what I'm talking about wanting to do the CPP modular spindles will be my best option. They will still push out my track width 3/4" on each side. But it's only that little bit and wayy less than other spindles. I think I can live with that, and looks like I can keep my wheels!

Couple more questions for you guys.
1. To run my 15" wheels will I need to run the 12" rotors or can I go with the 13"?
2. If I wanted to go 4 wheel discs (add discs in the rear) Would that affect wheel spacing and how much?
Thanks guys, sorry to be a bother. I'm sure all this has been covered before at some point. Just wanna get my facts straight for when I do all this.

[slick copper]

I can live with 12's. I'll just go with the drilled/slotted ones. And BIG thanks for all the info guys. That'll work on the rears. Guess I will upgrade to rear too that'll give me that little extra to compensate for the front.

[Captainfab]

Let me know if you are interested in one of my rear disc brake conversions.

Originally Posted by slick copper

I can live with 12's. I'll just go with the drilled/slotted ones. And BIG thanks for all the info guys. That'll work on the rears. Guess I will upgrade to rear too that'll give me that little extra to compensate for the front.

[slick copper]

I will! It'll be a little bit though. Gotta get this drop finished, and then get the tranny rebuilt. Brakes will be after that!

[LostMy65]

My 66 is a 3/4 ton, but the booster/master cylinder is from a 79 1/2 4x4.
Should I try and find a booster & master cylinder off a 3/4 ton, or will I be fine?

[Captainfab]

Some of the master cylinders on the 3/4 tons will be different than a 1/2 ton master, depending on the factory brake package. If your front calipers have the 2-15/16" bore, you can likely get away with that '79 K10 booster and master. If you have the 3-5/32" bore calipers, I would suggest a appropriate master. The masters will interchange with boosters regardless of 1/2 ton or 3/4 ton, at least with pre '99 trucks.

Originally Posted by LostMy65

My 66 is a 3/4 ton, but the booster/master cylinder is from a 79 1/2 4x4.
Should I try and find a booster & master cylinder off a 3/4 ton, or will I be fine?

[LostMy65]

Does this look like a 3-5/32 bore or a 2-15/16?
The front end was off a 79 1-ton.

Originally Posted by Captainfab

Some of the master cylinders on the 3/4 tons will be different than a 1/2 ton master, depending on the factory brake package. If your front calipers have the 2-15/16" bore, you can likely get away with that '79 K10 booster and master. If you have the 3-5/32" bore calipers, I would suggest a appropriate master. The masters will interchange with boosters regardless of 1/2 ton or 3/4 ton, at least with pre '99 trucks.

[Captainfab]

Ok, that does make a difference since you have a C30 front suspension and brakes. The 30 series trucks used an entirely different style caliper, with a bore that I believe may be bigger than 3-5/32". Is your 14 bolt from the same truck? I would definitely go with a master cylinder for a '79 SRW C30.

[LostMy65]

Originally Posted by Captainfab

Ok, that does make a difference since you have a C30 front suspension and brakes. The 30 series trucks used an entirely different style caliper, with a bore that I believe may be bigger than 3-5/32". Is your 14 bolt from the same truck? I would definitely go with a master cylinder for a '79 SRW C30.

I think the 14 bolt was just a 3/4 ton.

Can I atleast run the booster and master cylinder from the 1/2 ton suburban until I find a setup from a C30?
Posted via Mobile Device

[LostMy65]

Okay, I located a Master Cylinder off a 1 ton.
Did you say I'd be fine with the 1/2 ton booster off my 79 Suburban 4x4 donor?

Thanks for all the help.

Originally Posted by Captainfab

Some of the master cylinders on the 3/4 tons will be different than a 1/2 ton master, depending on the factory brake package. If your front calipers have the 2-15/16" bore, you can likely get away with that '79 K10 booster and master. If you have the 3-5/32" bore calipers, I would suggest a appropriate master. The masters will interchange with boosters regardless of 1/2 ton or 3/4 ton, at least with pre '99 trucks.

Posted via Mobile Device

[padresag]

Originally Posted by LostMy65

Okay, I located a Master Cylinder off a 1 ton.
Did you say I'd be fine with the 1/2 ton booster off my 79 Suburban 4x4 donor?

Thanks for all the help.

don't see why not. it is just a booster. my 1 ton doesn't have one, just push

ron

[LostMy65]

Originally Posted by padresag

don't see why not. it is just a booster. my 1 ton doesn't have one, just push

ron

That makes sense.
Thanks again.
Posted via Mobile Device