what are my gears?

i have a 71 buick skylark custom..350-4bbl..i know its not posi...but i dont know the gears..it is the orignal gears..and how much if possibale at all is it to switch to posi with the same rear end....and....what is the highest gear ratio i can go to....and how much is that?

thanks for all your help guys..im only 18

kyle

 

My guess is 254's or 273's

 

I would say you're car has a 2.56 rear end in it now, unless the original buyer ordered it with something special.

 

thanks steve, 256's is what I meant.

 

If it is an auto trans, it is a model 44437 and the standard rear in 1971 is a 2.73 with a 4 barrel and a 2.56 with a 2 barrel carb. The code stamped on your axle housing should be LLB. If it was special ordered with an economy rear, it would have been a 2.56 and if specially oredered with a performance 3.08. Most likely it is a 2.73.

 

thansk guys....any guesses on what it take and costs to get my dream posi with 393s?

 

You do not want that gear for a driver car even though you think you do. It is just not a practical gear to drive on the road. About a 3.08 to 3.31 is tops. I would not spend my money there to change it from the current one.

 

o ok ....my dad was like get 393s?..but ok..how much would 373s be with posi

 

Buickman71 I will be running 342's at 60 to 65 mph that will Put me at 3000 RPM. If you like driving 70mph+ suggest looking at 308 or 323's

 

I agree, I have 3.42's in my 71 350, I really wanted 3.23's, but could'nt get 'em for the 12 bolt. On any driver, whether its a small block, big block, GM, Mopar, Ford, or whatever, with a regular 3 speed auto, I feel 3.42 is just about maximum "practical" for extended highway driving. Mark

 

Hi Buickman71

For 1971 Buick changed the differential to the corporate 8 1/2 inch 10 bolt unit. Therefore changing gear ratios and putting in a posi carrier is relatively inexpensive.

Go with an Eaton posi carrier and aftermarket ring and pinion sets are available from a number of vendors.

Have somebody that knows their way around a differential set up the gears. That may end up costing as much as the posi carrier, but will last longer and run quiter with the investment.

Here is a vendor many of the Turbo Regal guys use for differential parts: Be sure to get the installation kit with purchase of the posi unit and gears.

Gears are us

 

thanks loyd for the info..will do