3.42 to 3.73 is it worth it?

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

  1. gocubs68

    gocubs68 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 All hail the Mad King!! Staff Member 5+ Years 1000 Posts Platinum Contributor

    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 Member

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

    MrShorty Epic Member 5+ Years 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 Epic Member 5+ Years 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 Epic Member 5+ Years 1000 Posts

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

    gocubs68 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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