Enjoy 5% OFF at VEVOR Canada! and Support Canadian Poncho at the Same Time!
Members Login
Username 
 
Password 
    Remember Me  
Canadian Poncho Homepage -> Canadian Poncho -> 65-70 Full Size Power Train Tech Forum -> What rear end ratio do I have?
Post Info TOPIC: What rear end ratio do I have?
cdnpont


Canadian Poncho Superstar!

Status: Offline
Posts: 10616
Date:
What rear end ratio do I have?
Permalink  

The HP post previous got me looking at the specs, and surprised I see that my 69 Parisienne 350/250 with the powerglide should have a 3.08.

I coud swear that it was a 2.73 as the car cruises along the highway no issue at 80 mph. No tach, but she feels like she's not working too hard at that speed.

250hp.JPG



Attachments
__________________
 67 Grande Parisienne 4 door HT. 69 Parisienne Convertible.
 
ABC123


Uber Guru

Status: Offline
Posts: 3556
Date:
Permalink  

It's too bad Vintage services never included this information.

As noted, you could order a different axle.

pontiac history2 (2017_01_29 18_50_35 UTC).jpg



Attachments
__________________

https://canadianponcho.activeboard.com/t63333628/click-here-to-support-canadian-poncho/

 
Nov 18 to Dec 2 Black Friday UP TO 50% OFF Plus Huge Coupons
Nov 18 to Dec 2 Black Friday UP TO 50% OFF Plus Huge Coupons
cdnpont


Canadian Poncho Superstar!

Status: Offline
Posts: 10616
Date:
Permalink  

So it's a 3.07 by default with the PG? 

Is it a 2.73 Randy?



__________________
 67 Grande Parisienne 4 door HT. 69 Parisienne Convertible.
 
Prefectca


Poncho Master!

Status: Offline
Posts: 1758
Date:
Permalink  

Its interesting in the 1969 Impala specs it lists 2:73 as the economy option. Just think if it was a big block the economy option was 2:29!IMG_7511.jpeg



-- Edited by Prefectca on Saturday 21st of October 2023 06:52:35 PM

Attachments
__________________
cdnpont


Canadian Poncho Superstar!

Status: Offline
Posts: 10616
Date:
Permalink  

2.29! Man that's high. BB wouldn't care.

The 69 B USA LM1 gets 5 more HP than the CP?



__________________
 67 Grande Parisienne 4 door HT. 69 Parisienne Convertible.
 
Prefectca


Poncho Master!

Status: Offline
Posts: 1758
Date:
Permalink  

cdnpont wrote:

The USA LM1 gets 5 more HP than the CP?

 It looks that way. I had to do an edit on the post. The top of the chart was cut off. 



__________________
seventy2plus2


Canadian Poncho Superstar!

Status: Offline
Posts: 7787
Date:
Permalink  

10 bolt or 12 bolt?
A 10 bolt ratio is 3.08, 12 bolt is 3.07.
What does the stamping on the front of the passenger side axle tube say? (assuming no one has changed the gears or diff)

__________________
70 2+2 convertible
70 2+2 hardtop
70 Parisienne hardtop

 

 
Nov 18 to Dec 2 Black Friday UP TO 50% OFF Plus Huge Coupons
Nov 18 to Dec 2 Black Friday UP TO 50% OFF Plus Huge Coupons
4SPEED427


A Poncho Legend!

Status: Online
Posts: 50193
Date:
Permalink  

My 69 Grande Parisienne 4 door hardtop 427 LS1 with air conditioning was built with 2.56 and I see in the chart that makes sense. Great diff, that 427 had no trouble with it. I pulled it out when I scrapped that car and put the diff in my 67 Grande Parisienne 396 wagon (also had air conditioning). Great combination, that 396 pulled over around 22-23 mpg on straight highway drives with the 2.56.

__________________

1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles 

1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)
cdnpont


Canadian Poncho Superstar!

Status: Offline
Posts: 10616
Date:
Permalink  

2.29 not available with PG or LM1/L48.

Makes sense. Might be a old dog off the line without a BB.

 



__________________
 67 Grande Parisienne 4 door HT. 69 Parisienne Convertible.
 
ABC123


Uber Guru

Status: Offline
Posts: 3556
Date:
Permalink  

This car is a dream on the highway but the only way to know for sure is to pull the cover and check for numbers.

The car is totally unlike any other 69 I have driven.

I'll bet the cover has never been off.

__________________

https://canadianponcho.activeboard.com/t63333628/click-here-to-support-canadian-poncho/

 
seventy2plus2


Canadian Poncho Superstar!

Status: Offline
Posts: 7787
Date:
Permalink  

Do you have the Protect-O-Plate for the car? If I recall the diff stamping is on there.

__________________
70 2+2 convertible
70 2+2 hardtop
70 Parisienne hardtop

 

 
ABC123


Uber Guru

Status: Offline
Posts: 3556
Date:
Permalink  

seventy2plus2 wrote:

Do you have the Protect-O-Plate for the car? If I recall the diff stamping is on there.

 Yes, somewhere, I will continue looking for it.

Thanks for the reminder !

I will find it Mark biggrin



__________________

https://canadianponcho.activeboard.com/t63333628/click-here-to-support-canadian-poncho/

 
Nov 18 to Dec 2 Black Friday UP TO 50% OFF Plus Huge Coupons
Nov 18 to Dec 2 Black Friday UP TO 50% OFF Plus Huge Coupons
LT1Caddy


Poncho Master!

Status: Offline
Posts: 1013
Date:
Permalink  


Jack it up, mark the driveshaft with chalk and turn the wheels...

__________________
65 SD L79


Canadian Poncho Superstar!

Status: Offline
Posts: 9521
Date:
Permalink  

LT1Caddy wrote:


Jack it up, mark the driveshaft with chalk and turn the wheels...

 x2



__________________
4SPEED427


A Poncho Legend!

Status: Online
Posts: 50193
Date:
Permalink  

I don't even do that any more. I just crawl under, mark the driveshaft, mark the bottom of the tire and watch the driveshaft while I do one full tire rotation. Even less effort (senior citizen thinking!)



__________________

1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles 

1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)
CdnGMfan


Canadian Poncho Superstar!

Status: Offline
Posts: 4956
Date:
Permalink  

The L65 (250 horse) & LM1 (255 horse) were the same engine except for the intake & carb. The L65 was the base Pontiac V8 for '69 & came with 10-bolt rears. The LM1 came with 12-bolt rear on manual cars & used Muncies rather than Saginaws (unlike the L65).

When the 327 was dropped from the Camaro during the '69 run, the L65 replaced the LM1 as the optional non-SS engine, & the 307 became base.
When the 327 was dropped from the full-size Chevrolet models late in the '69 run, the L65 became the base V8 & the LM1 was dropped.


3.07:1 rear ratio = 12-bolt 8.875" ring gear
3.08:1 rear ratio = 10-bolt 8.125" ring gear



__________________

67 Chevelle Malibu Sport Coupe, Oshawa-built 250 PG never disturbed.

In garage, 296 cid inline six & TH350...

Cam, Toronto.


I don't judge a man by how far he's fallen, but by how far back he bounces - Patton
Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.
Canadian Poncho Homepage -> Canadian Poncho -> 65-70 Full Size Power Train Tech Forum -> What rear end ratio do I have?
Tweet this page Post to Digg Post to Del.icio.us
.
Support Canadian Poncho!
Select Amount:
<
.
.
.