:canada: i have just swapped my drum brakesover to disc brakes by using the front pieces off a 1988 chev pickup. all i had to do was replace my bottom a-arm from a 1/2 ton to a 3/4 ton a-arm. the top balljoint was the same one but the bottom one had to be changed to a 88 ball joint. it pops right into the 3/4 ton a-arm. it only cost me 140.00 to do it as well. then your steering linkage just has to be adjusted to fit. i hope this helps somebody.

You have any pics? I am interested in how it looks.

i dont have any pictures yet, but will soon.

Damn thats a good idea, let us know how they perform and wear over time!!! My hats off to you!!:)

hello JHickson6: thanks for the reply. another good thing about this swap is the parts needed for this swap are the parts from a 1988-1993 truck including ball joints which are about 1/2 the price of 1968 ball joints.

So what you used was an 88 and up spindel? with which lower balljoint, the 88 and up half, or the older 3/4 balljoint. All this utilizing the older upper control arm using the halfton balljoint?

Definetly feel the 6 lug updated adaptation may be within reach here using the newer semi-floating 14 bolt rear.!!!!!!
(light 3/4ton, - 2500 series)

hello Chop Top: the 88 spindel, rotor, calipers, and ball joints were used in the swap. but you need a 3/4 ton 68 a-arm instead of the 1/2 ton one. the bottom 88 balljoint fits into the 68 a-arm, and the top 88 ball joint fits on the 68 a-arm. the top 88 ball joint you half to grind the rivets off of the 88 a-arm and then bolt it to the 68 a-arm. hope this clears it up. thanks!!!

can you post some pics love to see. did toy have to change your lines or power booster just wanting to know. love to do it if i can do it for cheep. the 900.00 kits are not for me
thanks
Darren

dream 69, Welcome to the board from Maryland. This sounds very interesting!. We would love to see some pics when you can. I don't drive my truck enough to justify the $700 kits either but would go for half of that if it's as simple as you say. I'm assuming you used the 88' 4x4 brakes to retain 6 lugs?. Did you use the newer style Master Cylinder and booster? Thanks.....Jim

I wonder if the 76 3/4 ton lower arm with do? Thats whats under mine now. I would love to try this setup. That would give me more reason to re-install the older style upper arm with new bushings. Is this going to change my track width any??

Hello chop top,
I believe the '76 3/4 ton lower arm is exactly the same but has a higher rubber snubber on it. So in my opinion it shouldn't change the track width any.
dream68

Dream 68, thats an interesting swap! how did the tierods work out with the 88 spindles?(or better put...which ones did you use?)

Dream68, Welcome aboard !!!!





That's the way I tried to do it, but didn't know the 3/4 ton was different. A friend gave me 2-1/2" drop spindles off of a newer truck, I bought everything to do the switch, But it came to a stop when I found out the lower ball joints were different, No one around here knew how to get around it. I went to Tuckers in Las Vegas and bought the complete disc brake,spindle kit from them.
Wish I would have known this then. would have saved me about $600.00.

That's nice about a board such as this, With so many people doing this stuff we learn most of the time the easy way instead of the hard way.....

hello 70C10: i am going to use the master cylinder and booster off a 70 1/2 ton. will work just fine.

I don't think that is going to provide you with enough fluid volume for the calipers.

2nd that chop top......the calipers will hang also with the residual valve on the drum master......

ok guys, which year master do you suggest?

71-72 I think would be the best, unless someone else has found another one that will bolt on our trucks.

dream 68, i have always been a beleiver in peel the parts off the same truck if you can. My 69 longhorn has ALL the pcs off a 75 C10(master, lines,hoses,prop valve,calipers,reardiff/brakes......yep, its a 1/2 ton ride now! I couldnt say for sure on your combo, but i dont like to mix em. Generally, the pcs that were designed together tend to work best together. Good luck.....crazyL:)

Crazy Longhorn: sorry so late getting back. i used the steering linkage from the 68. the tie rod ends fit the 88 spindle .

Crazy Longhorn: sorry so late getting back. i used the steering linkage from the 68. the tie rod ends fit the 88 spindle .

Thats cool, its sounds like it will get around all the center link/tierod issues that are involved with using the 71-72,or 73-87 pcs on the older trucks! :)

Dream68 youve got me thinking. Chevy made 6lug 2wd 3/4ton truck 88 up, so would the balljoints and evreything still work, I am wondering if the 6lug spindle is the same as the fivelug so i wouldent have to change the rearend.:confused:

GMC JUNKIE TOO: my 68 chev was a 6 lug before the swap , and is after the swap. all parts work as i have stated before.....

the 6 lug is the same...

awsome, it will be alot cheaper than $899.00 for 6 lug disc brakes evenafter the drop spindles.:D

dream68 can you elaborate on the 88 truck you got the parts off of. Was it a 1/2 ton or 6 lug 3/4 ton? I have Hollanders on my laptop and would be able to post some info for folks. Hollanders does show the 67-70 vs 71-87 3/4 ton lower control arms being different. Which did you use? I have heard you could use the 88-91 3/4 ton 2wd 6-lug rotors on 71-up spindles using 71-up calipers. I went to Autozone and had them pull a 71 1/2 ton 5-lug rotor and a 88 3/4 ton six lug rotor and they were basically the same and appeared to use the same bearing.

JJR: it was a 88 1/2 ton chev 2wd that all these parts came from. everything was ripped off the same truck, even the gearbox, but the gearbox will not fit...

Hollanders shows two spindles used on an 88 c1500 2wd. One for a 1" rotor and one for a 1 1/4" rotor. The spindle for the 1" rotor came on 88-91 c1500 and had a 1 1/4" inner bearing surface diameter. The spindle for the 1 1/4" rotor(which is probably what you have) came on the following:
CHEVROLET PICKUP TRUCK 88 2500 Series; 4x2
CHEVROLET PICKUP TRUCK 88-91 1500 Series; 4x2, 1-1/4" thick rotor
CHEVROLET PICKUP TRUCK 89-91 2500 Series; VIN models "C/K", 4x2, 6 bolt wheel
CHEVROLET PICKUP TRUCK 92-98 1500 Series; 4x2
CHEVROLET PICKUP TRUCK 92-98 2500 Series; 4x2, 6 bolt wheel
CHEVROLET PICKUP TRUCK 99 1500 Series; exc. Silverado; 4x2
CHEVROLET VAN 96-99 1500 Series
CHEVROLET VAN 96-99 2500 Series; 7300 lb. GVW
GMC PICKUP TRUCK 88 2500 Series; VIN models "C/K", 4x2
GMC PICKUP TRUCK 88-91 1500 Series; 4x2, 1-1/4" thick rotor
GMC PICKUP TRUCK 89-91 2500 Series; VIN models "C/K", 4x2, 6 bolt wheel
GMC PICKUP TRUCK 92-98 1500 Series; 4x2
GMC PICKUP TRUCK 92-98 2500 Series; 4x2, 6 bolt wheel
GMC PICKUP TRUCK 99 1500 Series; old style (flat, pull-up outside door handle), 4x2
GMC VAN 96-99 1500 Series
GMC VAN 96-99 2500 Series; 7300 lb. GVW
SUBURBAN 92 1500 Series; 4x2
SUBURBAN 93-96 1500 Series; 4x2, vacuum brake booster
SUBURBAN 97-99 1500 Series; 4x2, gas
TAHOE/YUKON 95-99 4x2

'95 up have ABS sensors on the brake shield.
1-3/8" inner bearing surface dia.
Inner bearing consists of #LM48548 cone & #LM48510 cup.
Heavy duty chassis option code is F44..

15981299 R.
15981298 L.


For lower control arm: the 67-70 3/4 lower arm can come from the following:
CHEVROLET FORWARD CONTROL 68-70 20 Series
CHEVROLET FORWARD CONTROL 68-70 30 Series; 7200 lb. rear axle
CHEVROLET PICKUP TRUCK 67-70 20 Series
CHEVROLET PICKUP TRUCK 67-70 30 Series; 7200 lb. rear axle
CHEVROLET VAN 71 30 Series; drum brake
GMC FORWARD CONTROL 68-70 2500 Series
GMC FORWARD CONTROL 68-70 3500 Series; 7200 lb. rear axle
GMC PICKUP TRUCK 67-70 2500 Series
GMC PICKUP TRUCK 67-70 3500 Series; 7200 lb. rear axle
GMC VAN 71 3500 Series; drum brake
SUBURBAN 67-70 20 Series
SUBURBAN 67-70 2500 Series


If the 71-up 3/4 ton lower control arm can work they can come from the following:
CHEVROLET FORWARD CONTROL 71-72 30 Series; 7200 lb. rear axle
CHEVROLET FORWARD CONTROL 71-89 20 Series
CHEVROLET FORWARD CONTROL 73-78 30 Series; non-removable carrier
CHEVROLET FORWARD CONTROL 79-84 30 Series; drum rear brakes, sgl. rear wheels
CHEVROLET FORWARD CONTROL 85-92 30 Series; exc. hvy. duty front susp.; drum rear brakes, sgl. rear wheels
CHEVROLET FORWARD CONTROL 93 30 Series; exc. hvy. duty front susp.; drum rear brakes, sgl. rear wheels, w/o 9L6 brakes
CHEVROLET PICKUP TRUCK 71-72 30 Series; 7200 lb. rear axle
CHEVROLET PICKUP TRUCK 71-88 20 Series
CHEVROLET PICKUP TRUCK 73-80 30 Series
CHEVROLET PICKUP TRUCK 81-88 30 Series; std. duty susp.
CHEVROLET PICKUP TRUCK 89-91 2500 Series; VIN models "R/V"
CHEVROLET PICKUP TRUCK 89-91 3500 Series; VIN models "R/V", std. duty susp.
CHEVROLET VAN 72-78 30 Series
GMC FORWARD CONTROL 71-72 3500 Series; 7200 lb. rear axle
GMC FORWARD CONTROL 71-89 2500 Series
GMC FORWARD CONTROL 73-78 3500 Series; non-removable carrier
GMC FORWARD CONTROL 79-84 3500 Series; drum rear brakes, sgl. rear wheels
GMC FORWARD CONTROL 85-92 3500 Series; exc. hvy. duty front susp.; drum rear brakes, sgl. rear wheels
GMC FORWARD CONTROL 93 3500 Series; exc. hvy. duty front susp.; drum rear brakes, sgl. rear wheels, w/o 9L6 brakes
GMC PICKUP TRUCK 71-72 3500 Series; 7200 lb. rear axle
GMC PICKUP TRUCK 71-87 2500 Series
GMC PICKUP TRUCK 73-80 3500 Series
GMC PICKUP TRUCK 81-87 3500 Series; std. duty susp.
GMC PICKUP TRUCK 88-91 3500 Series; VIN models "R/V", std. duty susp.
GMC VAN 72-78 3500 Series
SUBURBAN 71-88 20 Series
SUBURBAN 71-91 2500 Series

This statement makes for some confusion: This arm (71-up) may have two different ball joints one being light duty, the other being heavy duty. I am assumming they would be different diameters.

I hope this info helps.

WHOA!

JJR,the info given to me on the 3/4 tons(from local napa) is the ball joints interchange from 71-86 or 87 on the pickups. I didnt see his book, so it was just info given to me. I do know from experience that the 71 3/4 ton lower ball joint will press into the 67-70 3/4 ton lower arms, but the steer stops are different on the older arms(same deal as the 1/2 tons, it will shorten the turning radius), & will require a little grinding on the stops on the spindles to straighten it up.......crazyL

That is good to know Crazy Longhorn. The local pull-a-part tends to have a good selection of 3/4 ton trucks and occationally an 88-up. The get $15 for control arms and spindles. I have also seen several sets of 88-up spindles on e-bay go dirt cheap. People put drop spindles on and basically give away the old ones. Since a already have a set of 71 1/2 ton control arms and spindles and new ball joints for them, I will probably end up buying a set of 6-lug rotors and use what I have.

Cool!, This sounds like the next topic on the FAQ board, hopefully with a few pics!. Thanks guys.

Man, this is the reason I just love this site! This changeover will definetly be on my list of improvements I plan to make over the next 2 years. I'll be enrolling in the Auto-Body program at the local Community College and the instructor said I could use the school shop and tools after hours. Do any of you see any interference issues if I were to use an '88-'95 dropped spindle with this swap? Dream 68.............keep us informed and post any pictures. Great job!

OK GUYS: the steering linkage is a tad sloppy in the spindle, so this is what you do. use the 68 intermediate shaft with the 88 tie rods. the inside tie rod end is changed to PART# : MOOG ES2020RL.(tie rod end). This setup fits and looks like a dream with no binding anywhere. the 88 tie rods are also bulkier than the 68 original setup..... I will be in touch with more updates as i go... KEEP ON TRUCKIN MAMA!!!!

ALL PARTS NEEDED FOR BRAKE CONVERSION ON 68:::1968 1/2 ton top a-arm, 1970 3/4 ton bottom a-arm, 1988 1/2 ton ball joints(both), 1988 1/2 ton spindles, calipers, and rotors, 1968 1/2 ton intermediate shaft, 1988 1/2 ton tie rods, with the inner tie rod end changed to part#: MOOG ES2020. Brake lines can be changed if need be!!! GET TO WORK!!!

This is great info...but...anyone know if this will work for a 70:confused:

wnc mountain: i believe it should work because the boneyard told me the a-arms were the same from 68-70.

Thanks, I will have to give that a look. This may actually sway me to go with disks.

New to the group and just saw your conversion. Tell me, i've got a streetable 72 donor truck. Can the front brakes be easily swapped in to a 68? Both are nonpower.

I've followed this conversation with the understanding that this brake swap would apply for the 60-66. Can you offer your knowledge about this same swap applying to these year Chevys/GMCs?

I've followed this conversation with the understanding that this brake swap would apply for the 60-66. Can you offer your knowledge about this same swap applying to these year Chevys/GMCs?

Will this conversion apply to the 60-66 model Chevys and GMCs. I have a '63 GMC 6 lug that desperately needs more stopping power.

bump....

Has anyone else tried this conversion? It seems like a cheap way to add modern brakes to an old truck but I would like to hear from others that have tried it.

Now where to find a set of 3/4 ton lower control arms cheap?

nice job

Have you had it on the road yet...?

Was wondering if you felt any difference in the way it handled with the change..?

pics?

will the 73-87 stuff work? i've got a 86 frame im gonna be scrapping here in a couple weeks.

You can just put the front crossmember off the 86 on your frame. A search on disc brakes should give you a lot of info on this subject.

i already have discs on my truck...was wondering if it was any use to anyone else.

the 73-87 stuff will not work for this style conversion unless you someone wanted to buy the aftermarket 6 lug rotors...

the 73-87 stuff has 5 lug.

Exactly. Not to mention it is a TOTALLY different swap. Parts used to do the swap are different.

Any pics of this yet???

yes, it looks like this... been running it for a while now so it doesn't look as nice but you get the idea. I used a 1990 chevy front end/parts that had 5 lug 1.25" thick rotors and went to AutoZone and bought new factory 6 lug 1.25" thick rotors and bolted them on.
Good luck.

This is probably going to make a lot of disc brake conversion vendors mad :dohh:.

Expect prices to go up on 3/4 ton lower a-arms and the 88 parts, or they will probably package your idea and still sell it for $700-$1000.

Thanks firstgen, I appreciate it.

All in all, it's really not that cheap. I spent around $400 and I only bought what I had to plus two new rotors. You could easily spend $600 plus if you were buying all new bearings and rebuilding the calipers etc...

The only reason I did this swap was because I wanted to use all parts available at my local AutoZone, O-Riely's, etc. and not have to order special rotors from some company that could go out of business in 5 years.

Hey, FirstGen....

Can you provide any more detail about what exactly parts were necessary for your truck and what you got them off of? I've heard stories of people raiding 1994-1996 Impala/Caprice/Roadsters to get the 5-lug setup.

I am wondering if there is a need to get new a-arms (upper or lower), ball joints, tie rods or intermediate shaft with the method you chose?

I literally have the same truck as you (closer to stock though :D) - I would probably do mine a bit different, just looking for some direction.

TIA

Basically these are the parts I used:

1968 C20 lower control arms
1990 3/4 ton Light Duty 2X4 must have (1.25" rotors) spindles
1990 1.25" thick 6 lug rotors
1990 calipers off same truck
1990 upper and lower ball joints
1990 outer tie rods
inner tie rods MOOG part #ES2020RL
1990 style tie rod coupler


The only catch is to cut 3/4" off each end of both tie rods on each side of the truck so you can have enough room to align the truck. Well at least I had to since mine is lowered 4" in the front.

The front end I bought off the 1990 truck was 5 lug. All I did was went and bought the 6 lug rotors and bolted them on. If you wanted to stay with the 5 lug, you'd save yourself about $120 bucks.

After everything is done, you will now have 14mm studs on the front. I fixed this by drilling my rear axles and pressing in 14mm studs in the rear also but you wouldn't have to do this... I plan on going to a rear disc setup using a floating rotor design and so this helps that plan also...

Good luck.

what ball joints did you use?

what ball joints did you use?

if you read my last reply it's says 1990 upper and lower ball joints.

Thanks for the info, FirstGen. Did you need to modify your brake line or brake line assembly at all? I've noticed some people (normally in the back) welding on new L-brackets to hold the tap between the hard line and the flex line. Did you re-use all existing fittings and lines or buy new ones?

I used the rubber lines off the 1990 truck and used the factory mount from the 1990 to secure the line to the frame. Never ran new steel lines until later when I just wanted to, it wasn't nessary to do the swap.

DO you know if the 68 3/4 ton Lower A-Arm is the same as the 69? Thanks in advance for the help.

Bruce

DO you know if the 68 3/4 ton Lower A-Arm is the same as the 69? Thanks in advance for the help.

Bruce


I'm sure it is. Call Ed at Mothertruckers and ask him, he will know for sure...

DO you know if the 68 3/4 ton Lower A-Arm is the same as the 69? Thanks in advance for the help.

Bruce
Ask on the main board for confirmation, but I'm pretty sure they are the same as well.

I wonder if you can utilize the '88-'98 3" lift spindle while doing this swap....I'd like a little lift on my '70 C-10 Sub!!

Did anybody else that did this swap with factory ride height have serious alignment issues like I have??? Not toe, caster / camber...

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XIV. As of October 15th 2005 subscribing members will be the only ones permitted to post for sale and want to buy ads on any classified section of this site. All other rules of buying and selling still apply. 67-72chevytrucks.com, its administrators or staff are not responsible for any transactions on or off the forums. We will work hard to ensure you a smooth transaction, and help in the event you may need it, but all for sale and trade areas are buyer beware. Any persons who have misrepresented an item, lie about an item, fail to deliver, or are in violation of any of the rules will forfeit there subscription fees and be banned from 67-72chevytrucks.com

You two need to doing your buying and selling on the parts boards.

I think it was more or less a joke, but thanks!
Doc