FInding a Good 3.73 Diff for my '98
Safety Car
Joined: Mar 2005
Posts: 3,757
Likes: 1,215
From: Wisconsin
Since oem ratios we're 2.73, 3.15, 3.42 your looking for a used one that someone changed out to 3.73 with a ring and pinion swap. That will be hard to find. Post a want to buy ad in the forums parts for sale would be a start.
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
Agreed. Plus, if the OP does find one, it wont be cheap.....
Drifting
Joined: Jul 2004
Posts: 1,679
Likes: 692
From: Pingree Grove IL
1st gear 0-35 mph roughly
2nd gear 35-72,74 mph
3rd gear maybe 120mph
cruising at 80mph on highway, I’m at 2700RPM
i do HPDE and drag, times have improved on street tires. I’ve never run sticky tires yet.
I love the way the low gears feel in a C5 auto, converter definitely helps from a dig.
im just throwing this out there, because gears aren’t for everyone, highway gas mileage will definitely go down, I’m at about 22mpg highway. I used to be 26-27 with the 3.15 gears. I didn’t do gears because I wanted gas mileage. I wanted performance. Most of my driving out here on country roads are 0-70mph, I can bring 2nd gear up to top RPM everyday, and still be within speed limit range.
Good luck with your search. My advice is just get an RPM differential and be done with it. I have headers too, my car is pretty much ready for a top end rebuild at some point in the future.
Sorry for the long post.
Le Mans Master
Joined: Feb 2021
Posts: 6,511
Likes: 4,359
From: Florida
2025 Corvette of the Year Finalist - Unmodified
2024 C5 of the Year Winner- Unmodified
2022 C5 of the Year Finalist - Unmodified
Go to a vette mechanic and have them install new Motive gears. You buy used and you get the headache grab bag. And a do over is no bueno.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
Likes: 328
From: CA.
St. Jude Donor '13-'14-'15
I would not get a 3.73 It is a whole different set up Best advice would be to get a 3.42 out of a Z06 car
I went from a 2.73 to a 3.42 and was quite disappointed in the results--Very little acceleration gains
If you are looking for great hard launches the best mod you can buy is a higher stall converter !
The stock converter is like a lowly 1400 to 1600 Meaning when you launch from a dead stop and the converter stalls at 1400 you engine is only producing like 150HP and similar on TQ
Go to a 3000 stall Now when you launch and stall at 3000 you are now producing maybe 250 HP and TQ !!!! adding 100 to both All you are doing is skipping over the bottom low end RPM with low power Sorta like on a manual trans revving it up to 3000 and dumping the clutch AND a stall converter installed is way cheaper than doing a rear end swap JMHO
I went from a 2.73 to a 3.42 and was quite disappointed in the results--Very little acceleration gains
If you are looking for great hard launches the best mod you can buy is a higher stall converter !
The stock converter is like a lowly 1400 to 1600 Meaning when you launch from a dead stop and the converter stalls at 1400 you engine is only producing like 150HP and similar on TQ
Go to a 3000 stall Now when you launch and stall at 3000 you are now producing maybe 250 HP and TQ !!!! adding 100 to both All you are doing is skipping over the bottom low end RPM with low power Sorta like on a manual trans revving it up to 3000 and dumping the clutch AND a stall converter installed is way cheaper than doing a rear end swap JMHO
Le Mans Master
Joined: Feb 2021
Posts: 6,511
Likes: 4,359
From: Florida
2025 Corvette of the Year Finalist - Unmodified
2024 C5 of the Year Winner- Unmodified
2022 C5 of the Year Finalist - Unmodified
Nothing against a stall converter, but it requires the drivetrain to be pulled out. So the cost for that and the converter itself would be about the same as a gear swap.
If I was spending the $800+ for the drivetrain R&R anyway, I would do both the gears and a converter, and also service the torque tube. That combo would drive nicely on the boulevards and run like a big engine when you lay the hammer down. A great setup.
If I was spending the $800+ for the drivetrain R&R anyway, I would do both the gears and a converter, and also service the torque tube. That combo would drive nicely on the boulevards and run like a big engine when you lay the hammer down. A great setup.
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
Nothing against a stall converter, but it requires the drivetrain to be pulled out. So the cost for that and the converter itself would be about the same as a gear swap.
If I was spending the $800+ for the drivetrain R&R anyway, I would do both the gears and a converter, and also service the torque tube. That combo would drive nicely on the boulevards and run like a big engine when you lay the hammer down. A great setup.
If I was spending the $800+ for the drivetrain R&R anyway, I would do both the gears and a converter, and also service the torque tube. That combo would drive nicely on the boulevards and run like a big engine when you lay the hammer down. A great setup.
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Burning Brakes
Joined: Jun 2022
Posts: 758
Likes: 366
The gear swap is not easy trust me I’ve been down that road. Swapping the diff itself is easy though if you just buy a 3:42 takeout. At the end of the day it’s not going to transform the car the way a good converter would. If your swapping the diff your already half way there to swapping the converter.
