Disc Brake Upgrade Reference Thread

[Justins76]

I am getting all the parts together and I have 2 questions for you CaptFab.

1. I'm using the 6 lug rotors, same p/n as you posted. Is there a dust cap available? Everywhere I go says n/a.

2. Is the fitting on the 88+ brake hoses the same as the old inverted flair on the hard line or are they metric bubble requiring an adapter?

Thanks!

[Captainfab]

Originally Posted by Justins76

I am getting all the parts together and I have 2 questions for you CaptFab.

1. I'm using the 6 lug rotors, same p/n as you posted. Is there a dust cap available? Everywhere I go says n/a.

Well I haven't had to try and find one since I started with a donor '94 1500 that had all the small parts. It would seem like you should be able to find a dust cap for a '88-'98 pickup. I wonder if the '71-'87 dust caps would work. I'll see if I can find something out tomorrow.

Originally Posted by Justins76

2. Is the fitting on the 88+ brake hoses the same as the old inverted flair on the hard line or are they metric bubble requiring an adapter?

Thanks!

I'm pretty sure they are the metric bubble flare. I can verify that tomorrow as well as provide a part number for a metric to inverted flare adapter.

[Captainfab]

OK I have an update.

The dust caps for the '73-'87 C10 5 lug rotors will fit the '88-'98 6 lug rotors. Also the '88-'98 5 lug rotors use the same size dust cap. Those should be easy enough to find.

Regarding the front brake hoses. I checked one that I have from my '94 C1500 donor and to my surprise they are standard 3/16" inverted flare.

[Justins76]

Thanks. Just goes to show its a gamble whether GM used metric or US in the 80-90s.

[old_1966_GMC]

well i just picked up some 5 lug spindles today at half off price today at picknpull the spindles are from a 73 chevy what other parts do i need to make my 8 lug 65 c1500 gmc to 5 lug disc brake

[SCOTI]

Originally Posted by old_1966_GMC

well i just picked up some 5 lug spindles today at half off price today at picknpull the spindles are from a 73 chevy what other parts do i need to make my 8 lug 65 c1500 gmc to 5 lug disc brake

Spindle backing plates & bolts, calipers & bolts, rubber flex lines, rotors, seals, bearings, the correct BJ's (upper & lower) for the spindles, a disc brake master cyl, pwr booster (if you're converting to pwr brakes @ the same time), & the correct tie-rods/adapter sleeves so the disc spindle outer tie-rods work w/the drum spindle inner tie-rods.

[Captainfab]

Scot pretty much covered it.

You won't need the special tie rod adapters if you change the complete steering linkage for the '73-'87 assembly. There is another possibility on that, but I haven't been able to confirm yet that it will actually work.

I don't know for sure just what lower ball joints you will need to use, as I haven't done the swap quite like you're doing. The ball joint hole in the lower control arm is larger than the C10 ball joints. And you can't just change the lower control arm for the C10 unit since they mount differently. You may have to try a few different lower ball joints to find what will work. You might get lucky and the '63-'70 lower ball joint may work with the '73-'87 spindle.

That is why I mentioned earlier about using the '88-'98 spindle, since I know what works to do the conversion that way. Let us know what you find to work.

Originally Posted by SCOTI

Spindle backing plates & bolts, calipers & bolts, rubber flex lines, rotors, seals, bearings, the correct BJ's (upper & lower) for the spindles, a disc brake master cyl, pwr booster (if you're converting to pwr brakes @ the same time), & the correct tie-rods/adapter sleeves so the disc spindle outer tie-rods work w/the drum spindle inner tie-rods.

[old_1966_GMC]

then it would of been best to just find some 88-98 spindles or am i still ok with the 73's i got today, just have to try diffrent lower ball joint to see the best fitment.

also i would like some more info on tie rods part i just got done with school and learning collision repair so dont really know the mechaincal repair yet thats why im here to learn from u peeps

[Captainfab]

Here is one of my other posts on the subject of tie rods. However I don't know just what size your original C20 inner tie rods are as compared to the C10 inner tie rods. I wouldn't give up on the '73 spindles just yet....see if they will work with the '63-'70 lower ball joints first.

Originally Posted by Captainfab

The guys that use them get them from CPP, ECE and maybe POL. There are ways around buying those. One is to simply upgrade the entire steering linkage to the '73-'87 parts. Another way, but I haven't confirmed this, is to change your inner tierods to the ES2020L tierods. These will mate up with the '73-'87 outer tierods with the '73-'87 adjusting sleeve. But like I said, I haven't confirmed that those inners will fit the taper in the '63-'70 draglink.

Originally Posted by old_1966_GMC

then it would of been best to just find some 88-98 spindles or am i still ok with the 73's i got today, just have to try diffrent lower ball joint to see the best fitment.

also i would like some more info on tie rods part i just got done with school and learning collision repair so dont really know the mechaincal repair yet thats why im here to learn from u peeps

[old_1966_GMC]

are the upper and lower control arm interchangeable with frame and crossmember if so i migth just go and look for some this weekend

[Captainfab]

I'm not quite sure what you mean.

As I mentioned in post #132 above, you can't just switch the lower control arms. This is because the '63-'66 C20's have a flat lower control arm shaft that bolts directly to the crossmember. The C10's from '63-'87 and the C20's from '67-'87 both use round control arm shafts that sit in a saddle that is riveted to the crossmember and attached with U-bolts. Without making it difficult, you will have to change the front suspension crossmember if you want to use the C10 lower control arms.

A last minute thought here, you might be able to switch the control arm shafts from your C20 arms to a set of '63-'70 lower control arms. I'm not sure if the bushings are the same or not. If you decide to try this, be forewarned, changing the control arm shafts and the steel bushings can be a big pita unless you have the proper tools to do it.....even then.

Originally Posted by old_1966_GMC

are the upper and lower control arm interchangeable with frame and crossmember if so i migth just go and look for some this weekend

[old_1966_GMC]

i see what your saying the only way it would work is if i would switch crossmembers this will be the only way to remove the c20 lower arms and switch them to the correct c10 arms that would bolt rigth in. So in this case let say i did switch the cross member to a later model would i have any problem with the engine mounts as i tend to keep my stock 305.

[Captainfab]

I'm assuming you are referring to the 305 V6? I don't think you'll have any issues with using your existing engine mounts with the later model crossmember. As far as I know the later model cross members have the lower motor mount bracket holes in the same location.

Originally Posted by old_1966_GMC

i see what your saying the only way it would work is if i would switch crossmembers this will be the only way to remove the c20 lower arms and switch them to the correct c10 arms that would bolt rigth in. So in this case let say i did switch the cross member to a later model would i have any problem with the engine mounts as i tend to keep my stock 305.

[old_1966_GMC]

i think im ganna switch crossmember to make this a easy brake build oh yea its the 305 v6

[TheTurtleMan]

Ok, sorry I am sure this has been talked about somewhere in here but I couldn’t find it. Anyway I have a 66 short fleet, and I bought a 76 short step side to part out for my truck. I am really unsure what I want to do. Kinda wanna keep it 6 lug because I like my wheels and used 6 lug wheel are much easier to find. So what could I do to the 76 ft end to make it 6 lug? But if I go 5 lug anything weird with putting the 76 rear end in my truck. Sorry for the dumb questions. LOL

[raycow]

Originally Posted by TheTurtleMan

So what could I do to the 76 ft end to make it 6 lug? But if I go 5 lug anything weird with putting the 76 rear end in my truck. Sorry for the dumb questions. LOL

Not dumb questions at all.

6 lug rotors are available from CPP, Performance Online, and several other vendors. This is an aftermarket part that is a direct swap for the 5 lug. If your 66 has rear coil springs you can get a kit which contains weld-on brackets for the trailing arms and panhard bar. If you want 6 lug shafts for the 76 rear, you can use stock shafts for a 71-87 4WD. Your 66 shafts are too short for the 76 rear.

Ray

[Captainfab]

Welcome to the forum and hello neighbor

raycow pretty much covered it.

Let me know if you need a power steering box adapter or any of my other parts I make. No shipping since you can just come pick them up.

Originally Posted by TheTurtleMan

Ok, sorry I am sure this has been talked about somewhere in here but I couldn’t find it. Anyway I have a 66 short fleet, and I bought a 76 short step side to part out for my truck. I am really unsure what I want to do. Kinda wanna keep it 6 lug because I like my wheels and used 6 lug wheel are much easier to find. So what could I do to the 76 ft end to make it 6 lug? But if I go 5 lug anything weird with putting the 76 rear end in my truck. Sorry for the dumb questions. LOL

[TheTurtleMan]

LOL.... Thats funny. I was actually checking out your stuff but didnt look that you were in CDA. Ill post up a deal bout my truck. I got too many ideas and dont know what to do. LOL BTW, thanks for the help guys. If that 76 rear end is wider maybe Ill just keep mine, and keep it 6 lug.

[old_1966_GMC]

what also a good 5 lug rear end axle that would bolt in with my shaft im not quit sure if it has spring i think it has leaf spring for sure though

[fryer1979]

I've got a slightly different question for you guys that have done this swap already. After the swap is done, how is the ride height for a full '73-'87 crossmember and control arms in comparrison to the original '63-'66 front end? Does the truck sit any higher or lower? Mostly I am just curious in a stock for stock contrast. Thanks

[aggie91]

Originally Posted by fryer1979

I've got a slightly different question for you guys that have done this swap already. After the swap is done, how is the ride height for a full '73-'87 crossmember and control arms in comparrison to the original '63-'66 front end? Does the truck sit any higher or lower? Mostly I am just curious in a stock for stock contrast. Thanks

Back when I did mine, it did not change the height so that I noticed. I did not measure it to know for sure. I did not do the complete crossmember swap, i only did the spindle/rotor/caliper swap.

If the coil springs are the same, I mean the original ones were for a V8 and the swapped in ones were from a V8 truck (or 6 cyl/6cyl) the heights should be close not counting any amount of settling in the spring...

[old_1966_GMC]

1963-1966/5 lug
post#1

Parts Swap:
From '73-'87 you can unbolt the upper and lower control arms with the spindles attached and bolt these pieces onto your existing cross member. (clarification needed on 5-6 lug)

well i finally got the front suspension from a 76 chevy c10 during the weekend everything getting rebuild rigth now i had a few question the suspension wasnt removed by me when i got it they had a quy uninstall it for free there were these little y looking spacer on there how are those spacer supposed to go. every truck ive look today at pick n pull were all diffrent and last can i just bolt in the suspension on to my existing crossmember sence my 305e v6 is in and still running.

[Captainfab]

Those little 'Y' spacers sound like the shims for the upper control arms. Those are used between the upper control arm shaft and the part of the crossmember against the side of the frame. The shims are added or removed during the front end alignment process to adjust the caster and camber of the front wheels. There's really no way of knowing how many and what thickness to put where without doing a front end alignment. Yes you can bolt the '76 C10 control arms to your '66 GMC front suspension crossmember. As long as it isn't a 3/4 ton. I would recommend upgrading to the larger '76 U-bolts used on the lower control arm shaft. You will need to drill out the holes in the crossmember to do so.

Originally Posted by old_1966_GMC

well i finally got the front suspension from a 76 chevy c10 during the weekend everything getting rebuild rigth now i had a few question the suspension wasnt removed by me when i got it they had a quy uninstall it for free there were these little y looking spacer on there how are those spacer supposed to go. every truck ive look today at pick n pull were all diffrent and last can i just bolt in the suspension on to my existing crossmember sence my 305e v6 is in and still running.

[old_1966_GMC]

what should i do with the shims i mean can i just put them on how ever for now till its time to get a front end alignment

[Captainfab]

I would just keep track of the shims that are on your GMC right now. When you put the '76 control arms on, use the same shims that were on your truck to start with and in the same places. That will get you close enough to get your truck to an alignment shop.

Originally Posted by old_1966_GMC

what should i do with the shims i mean can i just put them on how ever for now till its time to get a front end alignment