C-1 rear differential for drag racing
#1
Le Mans Master
Thread Starter
Member Since: Oct 2007
Location: Richmond Kentucky
Posts: 5,722
Received 1,244 Likes
on
458 Posts
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
C-1 rear differential for drag racing
What is the best way to strengthen a C1 rear end for drag racing? OK, I KNOW the BEST way is to replace it with a 9 inch Ford (did I say that??) or a Dana 60. But is there anything that that can be done to the stock rear end to strengthen it? Different spider gears? Stronger axles? Aftermarket gears?
Looking for replies from the guys who have "been there and done that".
Thanks,
Rex
Looking for replies from the guys who have "been there and done that".
Thanks,
Rex
#2
Instructor
Currie Enterprises can build you a ford 9" with whatever brake setup or bolt pattern you'd like. The finished rear end is literally a bullet-proof bolt-in. Don't have one, but saw one go in. Don't look for the item on line, but call them for details. Definitely one good way to go.
Reed
Reed
#3
Le Mans Master
Member Since: Sep 2009
Location: "You may all go to Hell- and I will go to Texas- Davy Crockett
Posts: 9,151
Received 474 Likes
on
337 Posts
St. Jude Donor '12
You don't say what kind of engine you have, but the 8.2 Chevy can be strengthened quite a bit to handle more power. Yes, stronger gears, aftermarket axles and changing the spider and axle gears to the 30 spline 8 3/4 mopar internals will strengthen it a lot. The axles can be changed to Dutchman, or other after market, but they are still pretty small without going to a special oversize bearing, that requires machining the housing. Aubrey Bruneau has a billet cap that fits over the power side of the rear cap, that will help keep the carrier from being spit out the back end of the housing. Nobody that I know of makes a spool, so for me anyway, the best carrier is the 60-62 carrier. You can identify it by the left handed bolts that hold it together. It also has more clutches. After all that, you MUST not have any wheel hop, or you'll break the spiders. Running a 'soft' clutch, keeping the slicks to about 7 or 8 inches where it won't twist the pinion in two at clutch release, high numerical gears, and don't do 7,000 rpm launches, and it should do reasonably well, unless you are putting a lot of power through it. Auburn makes a Pro series center carrier that is probably stronger than the stock unit, but no one makes a heavy duty yoke, and the 1310 series u joint is all you can run. Using a solid joint will offer more strength.
Another option, that kinda sorta looks like the Chevy rear end is the 57-64 Pontiac rear end. It has massive axles, a bigger, stronger 9310 ring and pinion, will take big power, and I believe there is someone who makes a spool for it, a billet yoke, and billet caps for the case. They are really pricey, though.
PS- using a line loc to preload the gear so you don't 'shock' it will also help
Another option, that kinda sorta looks like the Chevy rear end is the 57-64 Pontiac rear end. It has massive axles, a bigger, stronger 9310 ring and pinion, will take big power, and I believe there is someone who makes a spool for it, a billet yoke, and billet caps for the case. They are really pricey, though.
PS- using a line loc to preload the gear so you don't 'shock' it will also help
Last edited by vettsplit 63; 01-02-2018 at 09:42 AM.
The following users liked this post:
Dr L-88 (11-12-2021)
#4
Race Director
We used to sell the Posi case with new machined caps. The spider gears and R&P were heat treated. The held up reasonably well, but remember back the (60s) most classes were limited to 7" slicks. We went to using Olds/Pontiac rears, but with a 6:17 ratio we still didn't get that many runs before they were torn up.
By the time you waste sourcing all the parts and the expensive it is easier, and in the end far better going to a 9" Ford rear. I had one made for my '62 a few years ago. Retained the drum brakes. Only very slight body modification was taking some of the radius off the spare tire well. I got enough off the clear and not go all the way through the well.
By the time you waste sourcing all the parts and the expensive it is easier, and in the end far better going to a 9" Ford rear. I had one made for my '62 a few years ago. Retained the drum brakes. Only very slight body modification was taking some of the radius off the spare tire well. I got enough off the clear and not go all the way through the well.
#5
Race Director
Member Since: Feb 2007
Location: northern california
Posts: 13,670
Received 6,625 Likes
on
3,033 Posts
C2 of Year Finalist (track prepared) 2019
What are you up to, Rex?
Expiring minds want to know....
Expiring minds want to know....
#6
Le Mans Master
Thread Starter
Member Since: Oct 2007
Location: Richmond Kentucky
Posts: 5,722
Received 1,244 Likes
on
458 Posts
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
#7
Race Director
Member Since: Feb 2007
Location: northern california
Posts: 13,670
Received 6,625 Likes
on
3,033 Posts
C2 of Year Finalist (track prepared) 2019
#8
Le Mans Master
Thread Starter
Member Since: Oct 2007
Location: Richmond Kentucky
Posts: 5,722
Received 1,244 Likes
on
458 Posts
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
#9
Safety Car
Member Since: Feb 2007
Location: Northern California CA
Posts: 4,522
Received 1,965 Likes
on
893 Posts
And....I've seen Jim's garage, so he's speaking from experience!
Happy New Year to you and your Mrs. Rex!
Pat
Last edited by ptjsk; 01-01-2018 at 06:11 PM.
#10
Le Mans Master
Thread Starter
Member Since: Oct 2007
Location: Richmond Kentucky
Posts: 5,722
Received 1,244 Likes
on
458 Posts
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
And here I am thinking about bringing something else into the stable. I must be .
Happy New Year to you and yours too Pat.
Rex
The following users liked this post:
ptjsk (01-02-2018)
#11
Race Director
Member Since: Feb 2007
Location: northern california
Posts: 13,670
Received 6,625 Likes
on
3,033 Posts
C2 of Year Finalist (track prepared) 2019
Well, Rex, I can help. Send me that trashy dual air meter FI unit and I'll haul it off to the landfill for you. I won't charge you anything for the service and afterward you can once again hold your head high.
#12
Race Director
Member Since: Jan 2000
Location: Corsicana, Tx
Posts: 12,639
Received 1,908 Likes
on
930 Posts
2020 C2 of the Year - Modified Winner
2020 Corvette of the Year (performance mods)
C2 of Year Winner (performance mods) 2019
2017 C2 of Year Finalist
Really good info here guys. Thanks! I haven't messed with a Chevy drop out chunk in years. Good to see there are still parts around to improve them!
JIM
JIM
#13
When enough time goes by people forget what was learned from past mistakes.
The original differential simply will not hold up to repeated dragstrip abuse no matter what modifications you make. This assumes you are running over 300hp.
These rearends were considered junk then and now for any serious HP.
The original differential simply will not hold up to repeated dragstrip abuse no matter what modifications you make. This assumes you are running over 300hp.
These rearends were considered junk then and now for any serious HP.
#14
Le Mans Master
Member Since: Sep 2009
Location: "You may all go to Hell- and I will go to Texas- Davy Crockett
Posts: 9,151
Received 474 Likes
on
337 Posts
St. Jude Donor '12
Tom, in your opinion, is the Eaton carrier stronger than the Dana type?
I remember back in the day, Jenkins was running 28 spline axles in his 63 Super Stocker (out of Chevy truck series I guess), and he drilled the rear housing and welded a reinforcement on the outside with a nut that was centered over each bearing cap. He had a bolt running through the nut and preloaded the bearing cap to help keep it from blowing the cap off the back of the case.
I remember back in the day, Jenkins was running 28 spline axles in his 63 Super Stocker (out of Chevy truck series I guess), and he drilled the rear housing and welded a reinforcement on the outside with a nut that was centered over each bearing cap. He had a bolt running through the nut and preloaded the bearing cap to help keep it from blowing the cap off the back of the case.
#15
Le Mans Master
Thread Starter
Member Since: Oct 2007
Location: Richmond Kentucky
Posts: 5,722
Received 1,244 Likes
on
458 Posts
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
Thanks Jim for your most generous offer. However, I don't want to offend Al Gore and Jerry Brown by contributing to "landfill waste" so I'll just send it to the aluminum recycler here in town. I think aluminum is up to $.026 per lb so I'll get about $14.76 for it. At least it will go to a good cause.............................new Coors and Budweiser cans.
Rex
#16
Race Director
Member Since: Mar 2001
Location: Mustang OK
Posts: 13,852
Received 3,777 Likes
on
1,676 Posts
2023 C1 of the Year Finalist - Modified
2015 C1 of the Year Finalist
Tom, in your opinion, is the Eaton carrier stronger than the Dana type?
I remember back in the day, Jenkins was running 28 spline axles in his 63 Super Stocker (out of Chevy truck series I guess), and he drilled the rear housing and welded a reinforcement on the outside with a nut that was centered over each bearing cap. He had a bolt running through the nut and preloaded the bearing cap to help keep it from blowing the cap off the back of the case.
I remember back in the day, Jenkins was running 28 spline axles in his 63 Super Stocker (out of Chevy truck series I guess), and he drilled the rear housing and welded a reinforcement on the outside with a nut that was centered over each bearing cap. He had a bolt running through the nut and preloaded the bearing cap to help keep it from blowing the cap off the back of the case.
Thus, today, a new Eaton and a new Nitro are probably a toss up. I like both and have installed both.
And the price is about the same for either one.
Last edited by DZAUTO; 01-02-2018 at 10:37 AM.
#18
Le Mans Master
Thread Starter
Member Since: Oct 2007
Location: Richmond Kentucky
Posts: 5,722
Received 1,244 Likes
on
458 Posts
2022 Corvette of the Year Finalist -- Modified
2021 C2 of the Year Winner - Modified
2021 C1 of the Year Winner - Modified
2020 Corvette of the Year (stock)
C2 of Year Winner (stock) 2019
2017 C1 of the Year Finalist
I'm looking at an ex NHRA Super Stocker. It has a Dana 60 in it now. I was just thinking the 9 inch Ford would look more like the stock rear end. But a Dana 60 would be strong for sure.
Thanks everyone for your comments. Take care and STAY WARM !!!!!
Rex
Thanks everyone for your comments. Take care and STAY WARM !!!!!
Rex
#19
Instructor
cheap way out
Tom