12 bolt rear diff cover - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**1971Stepside** · 08-14-2019, 09:35 AM

Went to order it and it shows out of stock...

KMC3420 · 08-14-2019, 11:19 AM

Quote:

Originally Posted by 1971Stepside

Went to order it and it shows out of stock...

Go figure. the part number is: A9070PBK, and when googling that, I found the below one.

Diff Cover

It shows as out of stock as well. You might email or call them to determine when these might be back in stock.

**1971Stepside** · 08-14-2019, 12:31 PM

Thank you for that. Looks like they are the same place. I called and he said 4 to 6 weeks. I will keep an eye on it. I don't have to have one right away.

KMC3420 · 08-14-2019, 12:41 PM

Quote:

Originally Posted by 1971Stepside

Thank you for that. Looks like they are the same place. I called and he said 4 to 6 weeks. I will keep an eye on it. I don't have to have one right away.

I will keep my eye peeled for a good straight one since your not far from me. I frequent the Springfield craigslist page.

Z10 · 08-18-2019, 12:44 AM

Picked this one up several years ago off ebay.

KMC3420 · 08-24-2019, 10:47 AM

Quote:

Originally Posted by Z10

Picked this one up several years ago off ebay.

Z10, that looks good! I saw it on eBay as well for roughly $70.

KMC3420 · 08-24-2019, 10:49 AM

I mounted my cover on and it fits as it should with no issues. I still need to sandblast and paint it, but I’m happy with the results.

KMC3420 · 08-24-2019, 10:55 AM

On another note I purchased ARP cover bolts and to my surprise they are too long. At this point I can grind the excess off and true the bolts up with my bench top grinder or stack washers which would be far less time consuming. Not sure if others have ran into this and ARP may make a shorter 12 bolt cover bolt. Sorry in advance for the sideways pictures.

**leddzepp** · 08-24-2019, 02:53 PM

The bolts that come with the aftermarket covers are too long as well. I just re-used my originals.

KMC3420 · 08-24-2019, 03:23 PM

Quote:

Originally Posted by leddzepp

The bolts that come with the aftermarket covers are too long as well. I just re-used my originals.

I purchased washers to use to decrease the length of the bolts, but am unsure if I will use them. I might just reuse my stock bolts.

KMC3420 · 08-24-2019, 10:39 PM

I did some more digging and the stock rear diff cover bolts are 5/16-18, .50” in length under head, serrated. The ARP bolts for a 12 bolt rear cover are 5/16-18 and .750” long under head, part # 437-3002. A more ideal ARP bolt to use would be the 612-0560 bolt, it is 5/16-18, .560 under head length and after using the washer the bolt is right at .50” in length under the head of the bolt while using the washer.
I know this is nerd bolt info but maybe it will help somebody down the road that is using the stock steel cover. The ARP .750” length bolts might work well with an aluminum cover if it’s a thicker casting.

ARP Bolts

68 P.O.S. · 08-25-2019, 10:43 AM

Nice, great info. Thanks for sharing!

Green Monster · 06-04-2020, 06:45 PM

Quote:

Originally Posted by KMC3420

Go figure. the part number is: A9070PBK, and when googling that, I found the below one.

Diff Cover

It shows as out of stock as well. You might email or call them to determine when these might be back in stock.

Thanks for sharing. Picked up front and rear black differential covers from Assault Racing Products to replace the chrome covers on my 72 Blazer. Less than $12 per cover plus $10 for shipping is a great deal.

https://www.assaultracing.com/item/4...-truck-12-bolt

KMC3420 · 06-04-2020, 10:35 PM

Quote:

Originally Posted by Green Monster

Thanks for sharing. Picked up front and rear black differential covers from Assault Racing Products to replace the chrome covers on my 72 Blazer. Less than $12 per cover plus $10 for shipping is a great deal.

https://www.assaultracing.com/item/4...-truck-12-bolt

They are nice pieces for the price! Mine was the same thickness as OEM.

Mike C · 06-05-2020, 08:07 AM

Quote:

Originally Posted by KMC3420

On another note I purchased ARP cover bolts and to my surprise they are too long. At this point I can grind the excess off and true the bolts up with my bench top grinder or stack washers which would be far less time consuming. Not sure if others have ran into this and ARP may make a shorter 12 bolt cover bolt. Sorry in advance for the sideways pictures.

Ahh posting on years old threads... Big Block Chevy/Pontiac oil pan bolts are the perfect bolt for the diff cover. I like to use stud kit on 2x4 trucks that aren't likely to be in rocks and keep bolts on a 4x4.

Canton stainless stud kit on Amazon less than $20. Same with Mr. Gasketbolt kit. And you get 20 of them instead of 10. Two sets will let you do 3 diffs with 4 extra bolts.

Green Monster · 06-05-2020, 11:11 AM

Quote:

Originally Posted by Mike C

Ahh posting on years old threads... Big Block Chevy/Pontiac oil pan bolts are the perfect bolt for the diff cover. I like to use stud kit on 2x4 trucks that aren't likely to be in rocks and keep bolts on a 4x4.

Canton stainless stud kit on Amazon less than $20. Same with Mr. Gasketbolt kit. And you get 20 of them instead of 10. Two sets will let you do 3 diffs with 4 extra bolts.

The price on Spicer differential bolts surprising ($1.41 ea to 16.99 ea)

An alternative would be nice.

Is this the Mr. Gasket Bolt Kit you are referring to?
https://www.amazon.com/Mr-Gasket-608...1369688&sr=8-7

Mike C · 06-05-2020, 09:04 PM

Yes, that 6086 kit is the big chevy/pontiac kit.

Here is the Moroso version:
https://www.amazon.com/Moroso-38560-...1405271&sr=8-1

The Canton stud kit:
https://www.amazon.com/Canton-Racing...1405285&sr=8-1

Milodon bolt kit:
https://www.amazon.com/Milodon-85005...405430&sr=8-17

Green Monster · 06-30-2020, 01:38 AM

Replaced the chrome differential covers front and back with black OE style covers. It looks cleaner in my opinion. Thanks for your help tracking these down for only $35.

KMC3420 · 06-30-2020, 09:52 AM

Quote:

Originally Posted by Green Monster

Replaced the chrome differential covers front and back with black OE style covers. It looks cleaner in my opinion. Thanks for your help tracking these down for only $35.

Sweet Blazer! I agree that the black cover does look cleaner as well.

**The Rocknrod** · 11-29-2021, 07:42 AM

Another bolt with a hex head in stainless (less cost)
https://www.boltdepot.com/Product-De...?product=17455
Or even less cost (zinc plated) Grade 5
https://www.ebay.com/itm/25210350877...8AAOSwvx5bYvjN

08-14-2019, 09:35 AM	#26
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Re: 12 bolt rear diff cover Went to order it and it shows out of stock... __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

08-14-2019, 12:31 PM	#28
1971Stepside Almost Satisfied Join Date: Mar 2002 Location: Springfield, MO Posts: 2,932	Re: 12 bolt rear diff cover Thank you for that. Looks like they are the same place. I called and he said 4 to 6 weeks. I will keep an eye on it. I don't have to have one right away. __________________ 1971 C10 Stepside. LSx 6.0 with BTR Stage IV, Speed Engineering Headers, 4L80e transmission w/3200 Circle-D Stall. 3.73. Posi. Purchased this truck when I was 17. I started the rebuild (or take apart) in 1993. I have drug it around all over the country in pieces. Finally back on the road in 2021. "I can't complain, but sometimes I still do. Life's been good to me so far."

08-18-2019, 12:44 AM	#30
Z10 Registered User Join Date: Aug 2012 Location: Midland, TX Posts: 1,267	Re: 12 bolt rear diff cover Picked this one up several years ago off ebay. Attached Images __________________ 1969 RS/SS Z10 Camaro Pace coupe 1972 GMC Short Step buildhttp://67-72chevytrucks.com/vboard/s...=1#post6356218 1979 Mazda RX7 1979 Pontiac Trans Am WS6 & 1979 Pontiac Trans Am 10th Anniversary 1999 Honda Valkyrie 2006 Corvette Z06 2010 BMW 650i

08-24-2019, 10:49 AM	#32
KMC3420 Registered User Join Date: Dec 2012 Location: Harrison, AR Posts: 1,067	Re: 12 bolt rear diff cover I mounted my cover on and it fits as it should with no issues. I still need to sandblast and paint it, but I’m happy with the results. Attached Images __________________ Keagan 68 SWB C-10 original 350 A/C 503 Mean Green

08-24-2019, 10:55 AM	#33
KMC3420 Registered User Join Date: Dec 2012 Location: Harrison, AR Posts: 1,067	Re: 12 bolt rear diff cover On another note I purchased ARP cover bolts and to my surprise they are too long. At this point I can grind the excess off and true the bolts up with my bench top grinder or stack washers which would be far less time consuming. Not sure if others have ran into this and ARP may make a shorter 12 bolt cover bolt. Sorry in advance for the sideways pictures. Attached Images __________________ Keagan 68 SWB C-10 original 350 A/C 503 Mean Green

08-24-2019, 02:53 PM	#34
leddzepp Moderator Join Date: May 2007 Location: Southern Cal Posts: 20,036	Re: 12 bolt rear diff cover The bolts that come with the aftermarket covers are too long as well. I just re-used my originals. __________________ 1972 C/10 Cheyenne Super SWB. Restored, loaded, slammed. 1968 C/10 50th Anniversary LWB. Unrestored, stock, daily driver/work truck. RIP ElJay RIP 67ChevyRedneck RIP Grumpy Old Man RIP FleetsidePaul

08-24-2019, 10:39 PM	#36
KMC3420 Registered User Join Date: Dec 2012 Location: Harrison, AR Posts: 1,067	Re: 12 bolt rear diff cover I did some more digging and the stock rear diff cover bolts are 5/16-18, .50” in length under head, serrated. The ARP bolts for a 12 bolt rear cover are 5/16-18 and .750” long under head, part # 437-3002. A more ideal ARP bolt to use would be the 612-0560 bolt, it is 5/16-18, .560 under head length and after using the washer the bolt is right at .50” in length under the head of the bolt while using the washer. I know this is nerd bolt info but maybe it will help somebody down the road that is using the stock steel cover. The ARP .750” length bolts might work well with an aluminum cover if it’s a thicker casting. ARP Bolts __________________ Keagan 68 SWB C-10 original 350 A/C 503 Mean Green Last edited by KMC3420; 08-25-2019 at 10:53 AM.

08-25-2019, 10:43 AM	#37
68 P.O.S. Registered User Join Date: Jan 2007 Location: Puyallup, WA Posts: 1,662	Re: 12 bolt rear diff cover Nice, great info. Thanks for sharing! __________________ 72 C10 lwb fleetside -stock 350/350 combo

06-05-2020, 09:04 PM	#42
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,728	Re: 12 bolt rear diff cover Yes, that 6086 kit is the big chevy/pontiac kit. Here is the Moroso version: https://www.amazon.com/Moroso-38560-...1405271&sr=8-1 The Canton stud kit: https://www.amazon.com/Canton-Racing...1405285&sr=8-1 Milodon bolt kit: https://www.amazon.com/Milodon-85005...405430&sr=8-17 __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

06-30-2020, 01:38 AM	#43
Green Monster Registered User Join Date: Mar 2006 Location: Malvern, PA Posts: 951	Re: 12 bolt rear diff cover Replaced the chrome differential covers front and back with black OE style covers. It looks cleaner in my opinion. Thanks for your help tracking these down for only $35. Attached Images __________________ Photo Gallery of 1972 K/5 Blazer CST

11-29-2021, 07:42 AM	#45
The Rocknrod Moderator Join Date: Aug 2011 Location: China Spring, TX Posts: 7,280	Re: 12 bolt rear diff cover Another bolt with a hex head in stainless (less cost) https://www.boltdepot.com/Product-De...?product=17455 Or even less cost (zinc plated) Grade 5 https://www.ebay.com/itm/25210350877...8AAOSwvx5bYvjN __________________ Master Chief, US Navy, Retired 1964 C10 Step-side Short Bed - In Progress 2009 2500HD Duramax LTZ 1948 GMC Panel 1956 Big Window Stepside 1953 5 Window Chevy Stepside 1932 Coupe New Seat Foam for Bench Seats?



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