Differential 3.73 ?
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Joined: Jul 2025
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From: Žilina
Differential 3.73 ?
Hi everyone, I have a 2001 Corvette C5 with an automatic transmission, and I’m considering changing the rear differential. Mine is a 2.73, and I’m thinking about going to a 3.73.Is that the right choice? Or should I rather go with a 3.42? I’ve seen that you can buy gear swap kits, which come out much cheaper than buying a complete differential. What do you think about this? Of course, I would have it installed by professionals who can set up the clearances correctly. Thanks.
Burning Brakes
Joined: Dec 2022
Posts: 1,025
Likes: 888
From: Nappytown MD
Don't forget to plan for a re-tune. You'll be able to drive it after it is swapped out, but you will need a re-tune as your shift points and such will be all wrong for that rear end ratio. Make sure you have someone lined up for that. I swapped my 2.73 rear end for a 3.42 from a Z I got off ebay and then went through it and freshened up seals and such. Love it-
Drifting
Joined: Jul 2004
Posts: 1,659
Likes: 684
From: Pingree Grove IL
I wouldn’t go that route. You shouldn’t cheap out on this mod. Get a stage 2, 3.73 gear from RPM transmission, transmission and diff come out together, I also did a Yank 3200 stall at the same time. If your worried about converter whine, this converter barely whines at all, I can even do a road course with this mod. It’s not cheap, but worth it. RPM takes your diff as a core in return.
Good luck and have fun with this. Do it and don’t look back.
Good luck and have fun with this. Do it and don’t look back.
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Joined: Jul 2025
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From: Žilina
[QUOTE=Beast;1609091311]Touto cestou by som sa nepustil. Na tejto úprave by si nemal šetriť. Zožeň si prevodový stupeň 2, 3,73 z prevodovky RPM, prevodovka a diferenciál vyjdú spolu, ja som zároveň robil aj zastavenie Yank 3200. Ak sa obávaš kvílenia prevodníka, tento prevodník takmer vôbec nekvíli, s touto úpravou dokážem dokonca prejsť aj cestnú dráhu. Nie je to lacné, ale stojí to za to. RPM na oplátku berie tvoj diferenciál ako jadro.
Veľa šťastia a bav sa s tým. Urob to a neobzeraj sa späť.[/QUOTE
Thanks for your message!What gear ratio would you recommend? Is 3.73 the right choice? Why isn’t it a good idea to just swap out the internals (gears, bearings, etc.) instead of the whole unit? I had a camshaft made that works fine with my stock torque converter, so I don’t really want to mess with that. I’d rather just upgrade the differential.
]
Veľa šťastia a bav sa s tým. Urob to a neobzeraj sa späť.[/QUOTE
Thanks for your message!What gear ratio would you recommend? Is 3.73 the right choice? Why isn’t it a good idea to just swap out the internals (gears, bearings, etc.) instead of the whole unit? I had a camshaft made that works fine with my stock torque converter, so I don’t really want to mess with that. I’d rather just upgrade the differential.
]
Thread Starter
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Joined: Jul 2025
Posts: 56
Likes: 1
From: Žilina
Thanks for your message!
What gear ratio would you recommend? Is 3.73 the right choice?
Why isn’t it a good idea to just swap out the internals (gears, bearings, etc.) instead of the whole unit?
I had a camshaft made that works fine with my stock torque converter, so I don’t really want to mess with that. I’d rather just upgrade the differential.
What gear ratio would you recommend? Is 3.73 the right choice?
Why isn’t it a good idea to just swap out the internals (gears, bearings, etc.) instead of the whole unit?
I had a camshaft made that works fine with my stock torque converter, so I don’t really want to mess with that. I’d rather just upgrade the differential.
Drifting
Joined: Jul 2004
Posts: 1,659
Likes: 684
From: Pingree Grove IL
These are not a standard 10 bolt or 12 bolt rear end from back in the day that you rebuild in your driveway. Just let the professionals do it, and be done with it. Yes. I spent a lot of money on my RPM diff, and Yank Converter, because I didn’t want my car screwed up. Save your Pennie’s and buy the best. And buy a 3200 converter from Yank. They literally drive like stock with a 3.73. As far as reliability, the yank 3200 SS series is probably the best around for reliability. People running this converter for 10, 15, 20+years.
If you’re completely confident in rebuilding your C5 diff, by all means, do it. Not me, can’t do that.
If you’re completely confident in rebuilding your C5 diff, by all means, do it. Not me, can’t do that.
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Joined: Jul 2025
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From: Žilina
I definitely wouldn’t be able to do it myself. But in our town, there’s a company that repairs differentials, drive shafts, etc. They work like on an assembly line and they’re very good. For them, it wouldn’t be anything unusual.
What I’m more interested in is the information whether, for example, a 3.73 differential from RPM is in some way better / higher quality compared to just having the internals replaced in my own differential (if done properly).
What I’m more interested in is the information whether, for example, a 3.73 differential from RPM is in some way better / higher quality compared to just having the internals replaced in my own differential (if done properly).
Drifting
Joined: Jul 2004
Posts: 1,659
Likes: 684
From: Pingree Grove IL
I don’t know what they use at your friends shop, look up the differentials at RPM on there website, it says what parts are in there. So, I’m not sure who’s are stronger. They refurbish the diffs, looked brand new when the shop installed mine.
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Melting Slicks
Joined: Sep 2018
Posts: 2,817
Likes: 174
From: Mid-Michigan
If memory serves from reading multiple threads about this over the years, you cannot install 3-series gears into the 2.73 differential. If you had the 3.15 diff to start with, you could. Would be best to find a lower mileage 3.42 Z06 diff, have that refreshed with new seals (and check the clutches and wave washers), and go from there. Also, if you do not want to go to a 3200 stall converter, you can use a higher-stall stock converter from an Astro van.
I recommend searching the forum and reading as much as you can about diff swaps before you even consider it.
https://www.corvetteforum.com/forums...-da-floor.html
https://www.corvetteforum.com/forums...ns-cooler.html
https://www.corvetteforum.com/forums...ld-how-to.html
https://www.corvetteforum.com/forums...-z06-guts.html
x3, you MUST revise your shift tuning to match the gear swap.
https://www.corvetteforum.com/forums...2-install.html
https://www.corvetteforum.com/forums...ng-issues.html
I recommend searching the forum and reading as much as you can about diff swaps before you even consider it.
https://www.corvetteforum.com/forums...-da-floor.html
https://www.corvetteforum.com/forums...ns-cooler.html
https://www.corvetteforum.com/forums...ld-how-to.html
https://www.corvetteforum.com/forums...-z06-guts.html
x3, you MUST revise your shift tuning to match the gear swap.
https://www.corvetteforum.com/forums...2-install.html
https://www.corvetteforum.com/forums...ng-issues.html
Thread Starter
Advanced
Joined: Jul 2025
Posts: 56
Likes: 1
From: Žilina
If memory serves from reading multiple threads about this over the years, you cannot install 3-series gears into the 2.73 differential. If you had the 3.15 diff to start with, you could. Would be best to find a lower mileage 3.42 Z06 diff, have that refreshed with new seals (and check the clutches and wave washers), and go from there. Also, if you do not want to go to a 3200 stall converter, you can use a higher-stall stock converter from an Astro van.
I recommend searching the forum and reading as much as you can about diff swaps before you even consider it.
https://www.corvetteforum.com/forums...-da-floor.html
https://www.corvetteforum.com/forums...ns-cooler.html
https://www.corvetteforum.com/forums...ld-how-to.html
https://www.corvetteforum.com/forums...-z06-guts.html
x3, you MUST revise your shift tuning to match the gear swap.
https://www.corvetteforum.com/forums...2-install.html
https://www.corvetteforum.com/forums...ng-issues.html
I recommend searching the forum and reading as much as you can about diff swaps before you even consider it.
https://www.corvetteforum.com/forums...-da-floor.html
https://www.corvetteforum.com/forums...ns-cooler.html
https://www.corvetteforum.com/forums...ld-how-to.html
https://www.corvetteforum.com/forums...-z06-guts.html
x3, you MUST revise your shift tuning to match the gear swap.
https://www.corvetteforum.com/forums...2-install.html
https://www.corvetteforum.com/forums...ng-issues.html
Melting Slicks
Joined: Sep 2018
Posts: 2,817
Likes: 174
From: Mid-Michigan
You are going to have to buy a different differential and retune anyway, so I would go with the 3.42 setup. It is my understanding that it works well with the stock LS1 cam, especially if you also upgrade the converter to go with it.
BUT, considering you've already upgraded your cam, I would start by asking whoever you bought the cam from if the gear change will be beneficial or not. It may be that for whatever it is you use the car for (daily drive or racing) the gear change could raise your rpms enough that it puts you out of the power band of the new cam.
BUT, considering you've already upgraded your cam, I would start by asking whoever you bought the cam from if the gear change will be beneficial or not. It may be that for whatever it is you use the car for (daily drive or racing) the gear change could raise your rpms enough that it puts you out of the power band of the new cam.
Thread Starter
Advanced
Joined: Jul 2025
Posts: 56
Likes: 1
From: Žilina
My camshaft will be very mild (I don’t have it in the car yet, it’s still being made). I’m really interested in the torque converter 24208645. It’s inexpensive and would probably meet my needs perfectly. The only problem is that I can’t seem to find it anywhere right now.
