8.5 to 9in differential swap

[Louie L]

Im contemplating a rear end swap on my Buick GN. My main question is how long is the pinion and yoke area of a 9in V/s a 8.5-10 bolt. I guess im all for shortening my brand new PST 3.5 CM driveshaft, but im not liking the idea of having to buy a complete new one if too short.

I then would have to make the 8.5 live for a while longer..

[Scott @ DLS]

They are very close if not the same distance depending on which pinion yoke you want to run. If you currently run a 1350 series driveshaft and have an assembly built with a billet 1350 Strange yoke you will be fine on the length. How much HP are you running and have you gotten a quote on a 9" yet?

[Louie L]

Scott,
I currently run a 1350 Moser Diff yoke on the 8.5.
My combo dynoed @ 1120 HP. Car currently weighs 3400 lbs w/driver.

I really wanted to keep that 8.5 but may not be able to.
Thats why I asked u about a 8.5 pro gear in another post.
I have not asked for a quote on a differential yet afraid of what it may cost. Plus im not familiar with the 9in.

[dougd]

Hi: I have one for sale , give me a call thanks doug

[Scott @ DLS]

Scott,
I currently run a 1350 Moser Diff yoke on the 8.5.
My combo dynoed @ 1120 HP. Car currently weighs 3400 lbs w/driver.

I really wanted to keep that 8.5 but may not be able to.
Thats why I asked u about a 8.5 pro gear in another post.
I have not asked for a quote on a differential yet afraid of what it may cost. Plus im not familiar with the 9in.


PM sent, let me know what you think.

Scott @ DLS

[KylePBZ]

When I went from the 8.5 to the 9" in my car my driveshaft was 1" too short. I found out that there are two lengths of 9" yokes(at least). The one that was on my 9" was the short one so I just swapped it out with a longer one and it's fine. Of course I'm not making enough power for a forged or billet piece yet so I'm not sure on those.