Disc brake swaps - pulling it together - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Chevyboy · 07-01-2002, 03:04 PM

Hello all!

I've been searching around the Board looking for info on Disc Brake swaps, and found some conflicting info... so I'm looking for some clarification.

I've got a '69 GMC 1500 2WD with 4 wheel drums. I know that '71 and '72 discs will work using all the components from the spindles-out, but I'd have to go to 5 lug, which I don't want.

If I want 6 lugs, (and this is where it gets fuzzy), I think I can use '73-'87 2WD components. If I understand it correctly, I can use the spindles, rotors, calipers, etc., but I'll have to use the '73-'87 ball joints and tie rod ends. Do I have to swap the cross member and A-arms in, too?

Also, I'd like to add a booster... does the '73-'87 one bolt right in?

**Classic Heartbeat** · 07-01-2002, 03:21 PM

If you want to stay 6 lug you will have to purchase a 6 lug disk brake conversion kit. 73 and later used 5 lug also.. We handle this kit if you are interested e-mail me at wehepp@attbi.com WES www.ClassicHeartbeat.com

Low69CST · 07-01-2002, 03:22 PM

You should get on early classic's website. For 269 bucks you get a pair of disc brake spindles that fit your balljoints and tie rods. With these spindles you don't need to change A-arms crossmembers or anything. Then you can get 6 lug rotors from early classic also. Then just get the wheel bearings, calipers, pads and your ready to go. Early classic has a complete kit, but it's 900 bucks. You may be able to get the pads and calipers cheaper at napa.

Some people like to pull the crossmembers out of junk trucks to get disc brakes. You can do this but then you've got used parts that you have no idea about. If all the ball joints, bearings, calipers are bad in your new crossmember, then you'll have to replace them, so what have you gained by switching crossmembers? If all your front end is good, i'd go the early classic route, i've had very good luck out of them.

To get power brakes, you need to get the fire wall bracket, get a different brake pedel rod, then buy the booster and mastercylnder at napa or somewhere and it bolts right up. You'll also need a disc/drum proportioning valve.

If you have any other questions just let me know.

70chevy · 07-05-2002, 03:55 PM

What about the brake lines. I have just installed 73 spindles, rotors, claipers, etc. I am sure the lines coming out of the calipers will have to be for 73 but what will be needed after the calipers?
Are not the 71 & 72 two different sizes?

Low69CST · 07-05-2002, 05:54 PM

I have 73 spindles and 72 calipers and 72 brakelines. I'm pretty sure that they are all the same. Try some 73 or 72 flex lines. I beth they'll work.

07-01-2002, 03:04 PM	#1
Chevyboy Registered User Join Date: May 2000 Location: CT, USA Posts: 20	Disc brake swaps - pulling it together Hello all! I've been searching around the Board looking for info on Disc Brake swaps, and found some conflicting info... so I'm looking for some clarification. I've got a '69 GMC 1500 2WD with 4 wheel drums. I know that '71 and '72 discs will work using all the components from the spindles-out, but I'd have to go to 5 lug, which I don't want. If I want 6 lugs, (and this is where it gets fuzzy), I think I can use '73-'87 2WD components. If I understand it correctly, I can use the spindles, rotors, calipers, etc., but I'll have to use the '73-'87 ball joints and tie rod ends. Do I have to swap the cross member and A-arms in, too? Also, I'd like to add a booster... does the '73-'87 one bolt right in?

07-01-2002, 03:21 PM	#2
Classic Heartbeat Project Junkie! Fishing Poor!! Join Date: Dec 1999 Location: Olympia,Wa. 98512 Posts: 10,766	If you want to stay 6 lug you will have to purchase a 6 lug disk brake conversion kit. 73 and later used 5 lug also.. We handle this kit if you are interested e-mail me at wehepp@attbi.com WES www.ClassicHeartbeat.com __________________ On-line catolog Classic Heartbeat Pickup Parts WEHEPP@comcast.net Call us Toll Free (888) 338-2502 Like Us on Facebook No appointment necessary. 72 BB Chevy Custom Deluxe / Custom Camper 67 I-6 (Soon to be 5.7 LS1) Panel 68 BB Chevy Short Bed 72 6.0 LQ9 Short Bed Chevy 4X4 Olympia's fastest growing truck parts supplier. Olympia's home for Wayward Chevys

07-01-2002, 03:22 PM	#3
Low69CST Registered User Join Date: May 2000 Location: Frankfort, Kentucky, USA Posts: 2,163	You should get on early classic's website. For 269 bucks you get a pair of disc brake spindles that fit your balljoints and tie rods. With these spindles you don't need to change A-arms crossmembers or anything. Then you can get 6 lug rotors from early classic also. Then just get the wheel bearings, calipers, pads and your ready to go. Early classic has a complete kit, but it's 900 bucks. You may be able to get the pads and calipers cheaper at napa. Some people like to pull the crossmembers out of junk trucks to get disc brakes. You can do this but then you've got used parts that you have no idea about. If all the ball joints, bearings, calipers are bad in your new crossmember, then you'll have to replace them, so what have you gained by switching crossmembers? If all your front end is good, i'd go the early classic route, i've had very good luck out of them. To get power brakes, you need to get the fire wall bracket, get a different brake pedel rod, then buy the booster and mastercylnder at napa or somewhere and it bolts right up. You'll also need a disc/drum proportioning valve. If you have any other questions just let me know. __________________ '69 CST Short fleetside Lowered, 400 small block, 700R4, 4 wheel disc brakes, front sway bar & rear camaro sway bar (in progress) '87 V10 4x4 Short Fleetside Quad Suspension and Dual Tanks Last edited by Low69CST; 07-01-2002 at 03:27 PM.

07-05-2002, 03:55 PM	#4
70chevy Registered User Join Date: Aug 2001 Location: Cherryville, NC Posts: 147	What about the brake lines. I have just installed 73 spindles, rotors, claipers, etc. I am sure the lines coming out of the calipers will have to be for 73 but what will be needed after the calipers? Are not the 71 & 72 two different sizes? __________________ Ken Smith 99 C5 Torch Red Coupe 85 Chevy Candy Apple 70 Chevy 1/2 in process.Semi-gloss black powdercoated frame & suspension, disc brakes up front, 3" drop spindle(Beltech) 5 lug 3.73 rearend, ZZ4, Sanderson headers, 700R4, Air Ride system, Summitt 16 gal fuel cell, Holly mech. fuel pump,

07-05-2002, 05:54 PM	#5
Low69CST Registered User Join Date: May 2000 Location: Frankfort, Kentucky, USA Posts: 2,163	I have 73 spindles and 72 calipers and 72 brakelines. I'm pretty sure that they are all the same. Try some 73 or 72 flex lines. I beth they'll work. __________________ '69 CST Short fleetside Lowered, 400 small block, 700R4, 4 wheel disc brakes, front sway bar & rear camaro sway bar (in progress) '87 V10 4x4 Short Fleetside Quad Suspension and Dual Tanks



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