WTB posi rear end

Discussion in 'Got gears?' started by Nick 66 Skylark, Dec 23, 2022.

  1. monzaz

    monzaz Jim

    The last one 67 Pontiac rear would be the best one i would purchase... Has the most potential. ...IN my opinion...
    Posi may need a reconditioning... But housing and gears etc look to be untouched and hoping all good running condition re bearing recondition posi and go.
    Jim
     
  2. BrianTrick

    BrianTrick Brian Trick

    As Jim mentioned,the 3rd link would be the one worth pursuing,to see if all is good. Jim can freshen up the unit. Then just replace all of the bearings & seals.
     
  3. Nick 66 Skylark

    Nick 66 Skylark Well-Known Member

    I noticed you currently have an open box carrier for sale on ebay. What are gear options with that unit?
     
  4. 12lives

    12lives Control the controllable, let the rest go

    I'm surprised you are considering a 3.42. Most 200r4 go with 3.73. How is it driving with the 2.78?
     
    sean Buick 76 likes this.
  5. Nick 66 Skylark

    Nick 66 Skylark Well-Known Member

    I'm open to input on gear options. I haven't heard from anyone with a 340 4barrel with the 200r4 and posi rear end with gear of choice or gear to not use
     
  6. BrianTrick

    BrianTrick Brian Trick

    The 8.2’s that I recently built for the same application got 3:55’s installed. There were no 3:42’s available. The black one was a 65 rear that I narrowed even more,so the customer could fit an old school wheel under his car.
     

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  7. Nick 66 Skylark

    Nick 66 Skylark Well-Known Member

    I went on Jegs and they didn't have a 3.42 either. It was 3.55,3.36 or 3.73. Still open to opinions.
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    3.73's will give you the best gear multiplication, and the 200R4 has a .67 OD. 3.73 X .67 = 2.4991 final drive. That means roughly 30 MPH/1000 RPM.




    If you use a 28" tire in the rear, the 3.73's become 3.55's. Stock tires are ~26.6" tall
     
    Last edited: Dec 26, 2022
  9. sean Buick 76

    sean Buick 76 Buick Nut

    Another vote for 3.73
     
  10. monzaz

    monzaz Jim

    CAMSHAFT will make all the difference on this - Plus rear tire size and converter stall and THE most important...How and where you will be driving your set-up.
    Jim
    Camaros in the 90's even had 2.73 and 3.23 in overdrive...BUT remember the camshaft profile is High torque lower lift - you do not stay in gears very long when popping through gears.
    Jim
     
  11. monzaz

    monzaz Jim

    ss monte carlos had 3.42 T types had 3.42 also GN came with the 3.73 and the 442 came with 3.73 -
    But again I can not stress enough on who is driving the car and What your car is going to do for you.
    If your just doing light to light city driving most of the time 3.73 4.10 are great!
    But if your going to be doing actual freeway driving 30mins and longer 3.42 3.55 will be a better choice.
    If you can not blow the tires off with a overdrive trans ...YOU have motor issues.
    we have a 250hp 350 Boat V8 in a monza with 2.56 gears and and it shreds the tires with a 2000 stall 350th and still goes great at 70 mph on the freeway.
    14.50 in the 1/4 mile...lol
    25" tires.

    IF your looking for all out acceleration gears are always going to give you that... But you will always compromise somewhere.
    You the customer have to figure out where most of your driving will be and then you can make the right decision...AGAIN cam shaft profile will be a big deal with gearing.
     

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