What is the stock ratio in a 1965 Cutlass convertible with Jetaway trans and 330 4bll. This is a Canadian car if that makes any difference.

 

I can't tell you exactly as there are at least five ratios standard, and two dealer ratios possible.

Do you know the code on the rear end, it will be two letters? AND are you sure its original? A lot of things can change in 45+years.
For example:
SA 2.78
SC 3.08
and others.
The only way to know for sure is to drop the cover. Fluid probably needs changed anyways.

Have you checked out this site. Its all about 65's. http://www.442bro.com/

 

I haven't got the car home yet so can't check the rear end. I've got fairly detailed info as to what's been done to the car in the last 15 yrs. and other than a recent oil change and new seals nothing has been done to the rear axle, but I can't say prior to that. Pretty sure the drive train is original tho.

 

It could also be a 2.93. The Oshawa cars sometimes got Buick rear end gear ratios instead of the more common Olds ratios. Both brands were built side by side and I pulled apart several 1965 F-85 and Cutlass cars that had the 2.93 set up.

Most likely it will be a 2.78 open rear end.

 

Thx for the info. Good to see so many Canadians sharing this forum along with our American friends.

 

For 1965, Cutlass (series 38), convertible (style 67), Jetaway, & V-8; the CSM says that it could be 3.23, 3.55, or 3.08. It looks like 2.78 was not used for this combination. It says that the 3.55 used a speedometer cable adapter with a 0.8653 to 1 ratio. Tires were 7.35 or 7.75 x 14. There is a code stamped on the housing. Sales information indicates that 3.08 was standard with the other two optional as "performance" ratios. All that's assuming that nothing's been changed. The surefire way is to remove the cover, count teeth and do some division. I don't know if the Canadian cars were treated differently.

 

The last statement is the key. This is an Oshawa built car & most were 2.78 & some were 2.93 or 3.08.

 

The SPECS manual shows that the standard ratio in a Cutlass with Jetaway was 3.08:1. 3.23 and 3.55 were options.

 

I guess they forgot to tell the guys on the line in Oshawa.

 

The SPECS booklets sometimes call out the Canadian-built cars in a footnote. This one did not. I don't know what the publishing date on this version was, either. There may be an update out there.

 

I have owned 8 Oshawa built 1964 1965 1966 Culass. 1 1964 had a 3.08 Posi and 1 1965 Cutlass had a 3.08 open. The other 6 were a mix of 2.78 and 2.93.

 

Thanks for all the info. Guess I'll have to wait till I can count teeth lol.

 

Do you have the RPO code list on the car? Assuming it's the orginal gear set