stock diff. ratios

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Apr 1, 2008 | 06:23 PM

ron69

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From: Gurnee Il

stock diff. ratios

Is there an easy way to tell the rear end ratio on a 1969 stock 300hp coupe? 3.08? 3.36?
Thanks
Ron

Apr 1, 2008 | 06:44 PM

Binnie77

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From: Halifax, NS, Canada

Well, it could be either. Your best bet is to look at the code stamped on the bottom lip of the case. Here are the codes:

http://corvettec3.ca/axle.htm#1969_Options

Apr 1, 2008 | 06:52 PM

ron69

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From: Gurnee Il

Thanks for the help, Binnie.

Ron

Apr 1, 2008 | 07:02 PM

another-user

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looks like ive got a 3.36 in mine. i thought it said GM on the plate, but it must have said AM.

Apr 1, 2008 | 07:55 PM

GTR1999

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From: Connecticut, USA

rule of thumb but does vary, base 4 spd had 336 auto's had the 308.
NOw some 4 spd's had the 308 as well and the HP engines had 336 355 370 or 411 options.

Apr 1, 2008 | 08:01 PM

Allen_396

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From: Madison Indiana

My late build '69 shows "CAM" on the bottom of the differential.

Apr 1, 2008 | 08:09 PM

dmayhew

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From: Brown Summit North Carolina

tell us what size rear tires you have and then also check the RPM's at 60MPH in 4th gear on a 4 speed and 3rd gear on a auto

There is a way to figure the ratio from that

David

Apr 1, 2008 | 08:29 PM

another-user

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no tach or speedometer it the car, so its abit hard to tell. sounds like its spinning at 2800ish at 60. not sure what size tires though. mines definatly a base 4spd, it was lacking just about every option except for being a vert and having a heater and FM radio.