Rear end ratio , 4:11 on 3.8L

[sully442]

I am going to change my 83 H/O with 455 to a Buick GN 3.8 . I have a Chevy 12 bolt with 4:11 in the rear now. How does the 3.8 work out with that steep of a rear gear? I may change them what is my best option?

Thanks
Sully

 

[Brad Zeidler]

Oh god!!!! You'd better at least have an overdrive transmission. An even fire V6 crank doesn't like to constantly be in that kind of upper rpm range. Being they don't have a common rod journal surface this becomes one of the breaking points from living in the upper rpm's.

 

[Pronto]

Turbo Buicks came with a 3.42 gear. LOTS of them run that gear in the tens, some beyond.

 

[UR50SLO]

I agree with Pronto..... Definatly get that gear out!

3:42's would be the best fit for the car... depending on how much power you plan on putting out with the Buick the less gear you'll need.

I run a 3:25 gear with a 28" tall tire and would still like to have like a 3:08 but not practial with my 9" rear.
Goodl luck with the swap!
~Scott

 

[sully442]

I will swap out gears. I am looking forward to not driving with them . I figured they were to much for the Buick set up. In all the posts I didn't see anyone talk about 4:11's.

I need a good shop south of Boston to help me Frankenstein my Hurst (again). Looking to paint it, new interior and swap 455 olds to Buick V6. Anyone have any suggestions?

Thanks
sully