Help with Brake Shoes Please?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*72longbed* · 03-06-2005, 09:41 PM

I need to replace the shoes (and just about every damn think else inside the drums) on a 1971 HO72 8 lug Rear axle. This is the HO72 that has the pinion tensioning bolt on the side of the center section.

So I go to the Advance Auto Parts and ask for a set of shoes and no less than four (4) different sizes come up in their computer for that year K20.

Does anybody know what the correct size shoe for a 1971 HO72 is?? I did bring with me the completely rusted relics that were on it, but the guy tends to think somebody put the wrong shoes on it at one time.

Also would be super helpful if someone could direct me to a good picture resource for the HO72 drum to drum?

Thanks,
72longbed

ckhd · 03-07-2005, 08:05 PM

I'll bet good money it's a HO52 - nearly the same as an HO72, but not quite has heavy duty.

'71 K20, it should be 12" x 2". Orig GM part no. looks to be 3933981.

If it was an HO72, it would have 13" brakes.

**JIMs70GMC** · 03-07-2005, 08:07 PM

I think the dana 60s had odd ball sized shoes. As was said should be 12x2 that's what's on my 71 K20.

Robert1970C20rstbukt · 03-07-2005, 08:09 PM

They should be 12" by 2 3/4" wide for the HO52. That's what they are on my truck.

ckhd · 03-07-2005, 08:15 PM

the four wheel drive rear drums were different than the two wheel drive. '71 two wheel drives had 11" x 2 3/4", four wheel drive had 12" x 2"

Not sure on '70, don't have as much info on them, but it looks like it should also be the same.

*72longbed* · 03-07-2005, 09:36 PM

I went to my buddy with the drum cutting machine and asked him what size brake shoes went inside the drums he had just cut for me. He took out his trusty tape measure and, sure enough, they are 2" x 12" that fit those drums.

BTW, its definitely an HO72 as evidenced by the 8 Lug hubs and the pinion adjusting bolt on the center chunk. The Detroit Locker from the factory also says its an HO72.

Did I read that somebody makes a disk brake conversion for these HO72's??

Or did I read that the kits for a 14 Bolt Full Floater also work on the HO72??

Anubody know the answer??

Thanks,
72longbed

Tx Firefighter · 03-08-2005, 08:08 AM

I believe the disc brake people are called Blackbird. There's a member here who is mixed up with them. Their website lists rear disc kits for all these old rearends.

Edit- I found their site.

click HERE

03-06-2005, 09:41 PM	#1
72longbed Account Suspended Join Date: Jun 2003 Location: PA Posts: 1,411	Help with Brake Shoes Please?? I need to replace the shoes (and just about every damn think else inside the drums) on a 1971 HO72 8 lug Rear axle. This is the HO72 that has the pinion tensioning bolt on the side of the center section. So I go to the Advance Auto Parts and ask for a set of shoes and no less than four (4) different sizes come up in their computer for that year K20. Does anybody know what the correct size shoe for a 1971 HO72 is?? I did bring with me the completely rusted relics that were on it, but the guy tends to think somebody put the wrong shoes on it at one time. Also would be super helpful if someone could direct me to a good picture resource for the HO72 drum to drum? Thanks, 72longbed

03-07-2005, 08:05 PM	#2
ckhd Registered User Join Date: Oct 2000 Location: St. Johns, Arizona Posts: 2,660	I'll bet good money it's a HO52 - nearly the same as an HO72, but not quite has heavy duty. '71 K20, it should be 12" x 2". Orig GM part no. looks to be 3933981. If it was an HO72, it would have 13" brakes. __________________ my 2¢ - t.i.o.l.i. Bowen 1968 K20 fleet 1969 K10 swb fleet 1972 K10 Suburban 1972 C10 lwb step 1992 K1500 'burb 1995 K2500 'burb 1997 C1500 'burb 1999 K1500 2000 K1500 'burb Why do I own so many Suburbans?

03-07-2005, 08:07 PM	#3
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	I think the dana 60s had odd ball sized shoes. As was said should be 12x2 that's what's on my 71 K20. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

03-07-2005, 08:09 PM	#4
Robert1970C20rstbukt Registered User Join Date: Jun 2004 Location: Beeville, Texas Posts: 1,943	They should be 12" by 2 3/4" wide for the HO52. That's what they are on my truck. __________________ RJD 1984 Chevrolet C30 welding truck 454/SM465 1977 GMC C15 pickup 350/TH350 1970 Chevrolet C20 pickup 350/TH400 1970 Chevrolet K20 Suburban 454/TH350 1969 GMC 8500 478M V6/5 spd winch truck

03-07-2005, 08:15 PM	#5
ckhd Registered User Join Date: Oct 2000 Location: St. Johns, Arizona Posts: 2,660	the four wheel drive rear drums were different than the two wheel drive. '71 two wheel drives had 11" x 2 3/4", four wheel drive had 12" x 2" Not sure on '70, don't have as much info on them, but it looks like it should also be the same. __________________ my 2¢ - t.i.o.l.i. Bowen 1968 K20 fleet 1969 K10 swb fleet 1972 K10 Suburban 1972 C10 lwb step 1992 K1500 'burb 1995 K2500 'burb 1997 C1500 'burb 1999 K1500 2000 K1500 'burb Why do I own so many Suburbans?

03-07-2005, 09:36 PM	#6
72longbed Account Suspended Join Date: Jun 2003 Location: PA Posts: 1,411	Found Out Size Today! I went to my buddy with the drum cutting machine and asked him what size brake shoes went inside the drums he had just cut for me. He took out his trusty tape measure and, sure enough, they are 2" x 12" that fit those drums. BTW, its definitely an HO72 as evidenced by the 8 Lug hubs and the pinion adjusting bolt on the center chunk. The Detroit Locker from the factory also says its an HO72. Did I read that somebody makes a disk brake conversion for these HO72's?? Or did I read that the kits for a 14 Bolt Full Floater also work on the HO72?? Anubody know the answer?? Thanks, 72longbed

03-08-2005, 08:08 AM	#7
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	I believe the disc brake people are called Blackbird. There's a member here who is mixed up with them. Their website lists rear disc kits for all these old rearends. Edit- I found their site. click HERE __________________ I'm on the Instagram- @Gearhead_Kevin



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