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Here is a 3.42 diff for $1200.00 with free shipping, says it has 72,000 miles and was pulled from a 2002 that was wrecked.
Have seen others for $1500 plus shipping, was looking for a friend who has 2004 C5 with 2.73 gears, I had pulled his drivetrain out to put in another torque tube he bought from local Corvette salvage place.
Tried talking him into swapping a used 3.42 diff while it was all tore apart, but he didn’t want to, oh well.
I’m one of the few that spent some money on a diff. About 4 years ago, I went with a stage2, 3.73 gear from RPM, and did a YankSS3200 stall. Those differentials are 2300 dollars, I didn’t want to go cheap on any part of the transaxle. It’s like the second heart of your Corvette, besides the LS1 being the main heart of your car. I wouldn’t buy a used diff with 70,000 miles on it, but that’s me, and not everyone is me. Love the steep gear feeling. I almost went with a 3.90, and YankSS3600, tuner talked me out of that. He said nobody does that unless you’re building a drag car. 3.73 is enough. 1st and second gear pull like a gorilla now. You need drag radials to really launch it. Summer tires won’t hold the pavement either. It’s better when temps outside are 85+ degrees. When temps are 50degrees, be careful.
Good luck with your rebuild. Have fun. My grin got bigger after the install. Should have done it 15 years ago after my warranty was up.
From: In a parallel universe. Currently own 2014 Stingray Coupe.
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A 3.42 gear change from a 2.73 or 3.15 will be a positive mod to the car. It has been a popular change to a C5 to enhance performance on the automatic equipped cars. Another good option is the 3.73 differential.
Obviously the trade off isn't for 'free' you will have higher RPM on the freeway. Which generally equals lower fuel mileage - which very few people in vintage sports cars care about.
For me - going from a 2.73 to 3.42 is a pretty significant change.
3.15 to 3.42 not so much; I'd probably jump the 3.73 at that point, but aftermarket gear ratios are over $2600
It is notable that the automatic has a much steeper first gear than either manual trans, so either way you'll get more results 'off the line'
