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3.42 to 3.73 is it worth it?

Discussion in 'GM Powertrain' started by gocubs68, Dec 16, 2008.

  1. gocubs68

    gocubs68 New Member

    My truck has an open rear end, and I am wanting to add a posi. But I just learned how to check the gear ratio by the RPO codes and found out that I have a 3.42 gear. I was just wanting to get some advice to see if moving to a 3.73 is worth it (don't want a 4.10 but not worried about the mileage loss to a 3.73), or should I just get a posi for my 3.42?
  2. Crawdaddy

    Crawdaddy Moderator Staff Member Platinum Contributor 1000 Posts

    unless something is causiing you to HAVE to replace the gears, then no, you won't nptice a real difference. That'd be like me moving from the 3.08s I have to 3.73... no real point.
  3. gocubs68

    gocubs68 New Member

    it's more of a want than a need, i don't tow anything.
  4. MrShorty

    MrShorty Moderator Staff Member 1000 Posts

    2wd or 4wd? If 4wd, you have to add in the cost of re-gearing the front diff as well (or converting to 2wd).

    What size tires are you running or planning to run?
  5. 95CTburb19

    95CTburb19 New Member 1000 Posts

    If you have to gear the front then no. If not then I might think about it. My dads old suburban had 3.73's and his new one has 3.42s as did my old one. There was a noticeable power difference in my dad's first one, and it had like 60k more miles than both his new one and my old one. :neutral:
  6. tlperry68

    tlperry68 New Member 1000 Posts

    Is there any need for it? If not I'd keep the same ratio.
  7. gocubs68

    gocubs68 New Member

    Truck is 4wd, It's totally a want. I am running stock size 265/70-17 but would like to eventually run a 33" tire. I am new to the truck and LS engine scene, as I have been playing with Mustangs for the last 5 or 6 years. And I'm wishing I would have done some research and bought a Z-71 with a 5.3, 3.73 gears and a posi, but I didn't. I've got some money to put in the truck, and I'm very unsure of what parts would benefit me the most. My 4.8 is pretty weak, and I know that gears will give it some more acceleration, and 3.73's won't affect my mileage that much. The truck only has 30k miles.

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