Rear End, 67 L79

[Steve P.]

I am about to purchase a 67 Corvette Coupe L79. The engine and running gear appear to be stock. I am curious as to the rear end ratio. Any suggestions?

thanks in advance.

[Ara G.]

Re: Rear End, 67 L79

What's your question? The L79 engine could be equipped with many different rear ends. A simple peek under the backend will, if original, tell you what ratio you have. Buy the Pocket Spec guide from the NCRS store. It has all the rear end codes as well as a TON of additional info on these wonderful cars. Good luck. ARA

[John D.]

Re: Rear End, 67 L79

steve
Take a look at the bottom flange of the differential at the cover- there should be a date stamp and a two letter code that begins with the letter A if it's the original case. For example my 67 L79 with the M20 (wide ratio) manual is stamped AM which is 3.36. AK would be 3.36 in a non posi.

other codes
AL 3.08
AN 3.55
AO 3.70
AP 4.11

[Leif A.]

Re: Rear End, 67 L79

Steve,
As mentioned above but here's a picture of what you're looking for. The "AS" is a 3.70 non-posi.

[Gary J.]

Re: Rear End, 67 L79

True the code will give you an idea of the rear ratio but that does not necessary means that is the ratio. These things have a way of being changed, for example a 3.70 could now be a 3.08 in that is in the rear end housing.

[Tim G.]

Re: Rear End, 67 L79

It' easy to lift the rear end, mark the drive shaft and count the revolutions for a 360 spin of the rear wheel.

Also, the 1967 sales brochure calls out RPM at various ratios as below. This was helpful for buyers to see what ratios they wanted for their needs.
Here is the information from the sales brochure.

Miler per hour per 1000 engine RPM in final drive.
3.08=25.6
3.36=23.1
3.55=22.1
3.70=21.3
4.11=19.2