Rear End Ratio
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Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Rear End Ratio
Any way to tell what the rear end is without riping into it?
I have an 81 L82 w/auto. Thinking seriously about swapping in a 200r4 for the overdrive and want to take advantage of gearing to get it some more pep off the line and better hiway manners. Suggestions?
I have an 81 L82 w/auto. Thinking seriously about swapping in a 200r4 for the overdrive and want to take advantage of gearing to get it some more pep off the line and better hiway manners. Suggestions?
NCM Grand Opening Veteran
Joined: Sep 2005
Posts: 20,979
Likes: 384
From: South of giving a damn
St. Jude Donor '11, '17
My Corvette Restoration Guide lists only 2 rearends for an 81
OJ - 2.87 - Posi for auto
OK - 2.72 - Posi for manual
The code is on the bottom of the case, but it's safe to assume that it's the 2.87, unless you have reason to believe that a previous owner changed it.
OJ - 2.87 - Posi for auto
OK - 2.72 - Posi for manual
The code is on the bottom of the case, but it's safe to assume that it's the 2.87, unless you have reason to believe that a previous owner changed it.
Melting Slicks
Joined: Dec 2005
Posts: 2,441
Likes: 0
Lift the car up and support the rear wheels as though they were on the ground, under the shock mount with jackstands is a good place. Put the car in neutral, get under the car and mark the drive shaft with some chalk, then mark an adjacent area on the frame for reference, like lining up the damper mark with the timing mark at top dead center on an engine. Now make a similar reference mark on a rear tire and a stationary point. Spin the driveshaft and note the revolutions the rear tire makes. If the driveshaft made 2.87 turns for every one revolution of the tire, then you know that your ratio is 2.87.
Last edited by shafrs3; Feb 12, 2006 at 07:06 PM.
The opposite is actually true. You are going to reference how many times the DRIVESHAFT rotates for ONE relolution of the WHEEL!
