240 rear gear

1975 - 1979 Mopars

  1. gdking11

    gdking11 New Member

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    can anyone tell me what i need to be concerned with when changing a standard 79 8.25 2.40 rear gear to 4.56? Thanks
     
  2. WP29440SE

    WP29440SE Well-Known Member

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    a 2.4 rear gear? im pretty sure the highest was a 2.76 ,but any way i would be looking at an 8 3/4 for that kind of ratio. 8 1/4 rears are not exactly the greatest for performance . i didnt know you could get a 4.56 ring and pinion for an 8 1/4
     
  3. rumblefish360

    rumblefish360 Well-Known Member

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    No, there was the 2.45 ratio,.

    The carrier will need to be changed to a carrier from a higher gear ratio, the 2.76 carrier will do. However,a new suregrip unit is around $300 IIRC, or last I seen.
     
  4. gdking11

    gdking11 New Member

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    so the 4.56 won't work out of the box?
     
  5. rumblefish360

    rumblefish360 Well-Known Member

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    I do think that is what I said, read the above post. ;)
     
  6. WP29440SE

    WP29440SE Well-Known Member

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    why are you wanting a 456 gear. are you building a door slammer cordoba? wheres the pics
     
  7. gdking11

    gdking11 New Member

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    79 magnum...oval track car. Can't get quite enough revs with gear ratio. i'll see what i can do about pics
     
  8. guitarguy

    guitarguy Well-Known Member

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    Main thing to worry about is ending up in the back seat after you romp on it the first time after the swap. :headbang:
     
  9. Citrus1973

    Citrus1973 Banned

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    I just got my 'Doba back today from having gears installed. I purchased a used sure grip including 3.90 gear set off ebay. It reall y has made a big improvement. I had 2.7 gears original. Now to make this wretched 318 breath...
     
  10. m79ded

    m79ded Well-Known Member

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    100% agree with SUPER77SE 8.75 is the way to go just get rid of 8.25.
    And besides when you will want to change gears for different tracks it is a real breeze just swaping the center section.
     
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