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Old Aug 17, 2007 | 07:58 AM
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How can I tell what gear size I have in 77 corvette doing a rebulid with about 320-350 hp just wondering if I should change gears this is mostly for street I already have trailing arm ,spring out just thinking with everything out if I need to do anything with the rear end
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Old Aug 17, 2007 | 08:01 AM
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Originally Posted by glo
How can I tell what gear size I have in 77 corvette doing a rebulid with about 320-350 hp just wondering if I should change gears this is mostly for street I already have trailing arm ,spring out just thinking with everything out if I need to do anything with the rear end
I am about to swap to a 3;73 in my 82 my stock is 2.72 yours is probably 3.03 or something like that.
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Old Aug 17, 2007 | 08:14 AM
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Turn the halfshafts one full revolution and count how many times the driveshaft rotates. This is your ratio.
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Old Aug 17, 2007 | 08:15 AM
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Originally Posted by glo
How can I tell what gear size I have in 77 corvette doing a rebulid with about 320-350 hp just wondering if I should change gears this is mostly for street I already have trailing arm ,spring out just thinking with everything out if I need to do anything with the rear end
Axle codes are stamped on the bottom of the differential carrier housing just forward of the cover,check your code against these codes for the 76/77 model

OA 3.08:1
OD 3.36:1
LR 3.36:1
OB 3.55:1
OC 3.70:1
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Old Aug 17, 2007 | 08:16 AM
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It will be a 3.08, 3.36,3.55,3.73 or possibly 4.11. Take your axle coming out of the rear and spin it exactly ONE revolution and count the number of times the driveshaft goes around. 3 1/4 times you have a 3.36, 3 1/2 times a 3.55 and so on. If the halfshafts and tires are still on just rotate the tire exactly ONE revolution and count the driveshaft revs.
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Old Sep 20, 2007 | 11:43 AM
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I have a 3:08 in right now. What would be the difference in going up a level or two? Mechanic said 4:11 wouldn't be a good daily driver??
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Old Sep 20, 2007 | 12:24 PM
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For a stock L-48, I think a 3.36 would be a good upgrade. If it was a warmed over 350, I might consider a 3.55, it just depends on how often you drive the car.
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Old Sep 21, 2007 | 02:58 PM
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Went w/ a 3:55 from Ikerds (sponser on here). Time will tell, once it gets here and is installed! thanks for all your help S!

David
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Old Sep 21, 2007 | 08:34 PM
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Originally Posted by glo
How can I tell what gear size I have in 77 corvette doing a rebulid with about 320-350 hp just wondering if I should change gears this is mostly for street I already have trailing arm ,spring out just thinking with everything out if I need to do anything with the rear end
As long as you have everything apart, take off the diff cover and take a good look at the internals. If everything is good it will only cost you a gasket, and the fluid probably needs to be changed anyway. If there is excessive play in the yolks (more than 1/16" or so - opinions differ) or the ends of the yolks are mushroomed you will need to do a rebuild. If a rebuild is needed you can decide on what gears you want to use.



Rick B.
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Old Sep 21, 2007 | 11:26 PM
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I'm not much for just posting icons but here goes
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Old Sep 23, 2007 | 01:24 PM
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I put 4.10's in and it is a little much esp with a 3 speed auto. Although it is crazy off the line.
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Old Oct 2, 2007 | 09:35 PM
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Originally Posted by bluesilver82
I am about to swap to a 3;73 in my 82 my stock is 2.72 yours is probably 3.03 or something like that.
Damn, 2.72 that sucks. I also have an 82 and I am running a T56 6speed. I am going to put in 4.10's. Do you know what rearend is on our cars? I heard somewhere that they were Dana 38's. Also which carrier is in there? Did you need to change the carrier for the new gears?

thanks,
Josh
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