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    Gear Ratio ?

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    jimzagg
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    Gear Ratio ?

    Post  jimzagg on Fri Apr 07, 2017 6:47 am

    Newbie here ! My 1984 Delta 88 Daily Driver Has a rebuilt 307 with a Holley carb and an Edelbrock Performer intake and an HEI with vacuum advance. It has a turbo 350 with a stock converter. My problem is with the 2.41 gears in the 7.5 rear it is just too lazy to drive normally on the road. I'm thinking about switching to either 2.73 or 3.08 gears. Not knowing much about 7.5 rears my question is do I need to switch the carrier in the rear? Have any of you guys done this and any preference on ratios?

    JIM

    BrokenBlazerDave
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    Re: Gear Ratio ?

    Post  BrokenBlazerDave on Fri Apr 07, 2017 6:48 pm

    According to Motive Gear's website the carrier break is between 3.08 and 3.23 for the 7.5" rear end. So with your numerically lower ratio's you would not need to change the carrier. To keep the cost down I would probably go with the 3.08. You would get the most bang for your buck around town and still not rev too high on the highway and not have to replace the carrier. The only reason to replace the carrier would be if you wanted a limited slip. With all the vehicles listed you shouldn't have too much trouble finding a cheap rear end with the gears you want and maybe even a posi.
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    jimzagg
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    Gear Ratio ?

    Post  jimzagg on Sat Apr 08, 2017 5:35 am

    Thanks Dave ! I was kind of leaning toward the 3.08 gears myself.
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    Re: Gear Ratio ?

    Post  GM B-Body Forum on Sun Apr 09, 2017 4:52 pm

    Yes a 3.08 is perfect, i ran a 3.08 for a few years. Started out with the original 2.41 in the 7.5, swapped in an 8.5 from an impala ss which had the 3.08, then now ive got 3.90s. The 3.08 was perfect all around. Its not my daily so i went with 3.90s which arent bad for the street but the highway i can hit about 3200rpm at about 70


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    1979 Caprice Sport Coupe, 400hp Vortec 350, Th350, GM 8.5 w/disc brakes, 3.90 gears Detroit Truetrac, 2.5" stainless duals w/ x-pipe, Dynomax race bullets.
    1984 Caprice Sedan, 305 motor, 700r4
    1978 Caprice Sedan, 305 motor, th350
    1993 L99 Caprice, 4.3 v8, 4l60 trans
    1972 Ford F-100, 302 windsor, c4 trans
    2001 BMW E46 330i, 3.0L
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    jimzagg
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    Re: Gear Ratio ?

    Post  jimzagg on Tue May 16, 2017 5:55 am

    I Found a set of 3.08 used take out gears at Spring Carlisle. I am in the middle of doing the install and will keep you guys posted to the results. I'm also thinking about installing an 8.5 impala disc rear in my other OLDS and putting a Stroker Smallblock in it and building a Gentlemen's Hot Rod. The 8.5 has a 5x5 bolt pattern. Have any of you guys researched the possibility of the Impala rotors (1995) fitting my OLDS (1984) spindles or swapping the complete spindle assemblies? Thanks for the info !
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    Re: Gear Ratio ?

    Post  jimzagg on Thu May 18, 2017 6:07 am

    Gears are in ! Drives much better !!! Now to fix the fuel tank sending unit !!! Then the sagging head liner !
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    Re: Gear Ratio ?

    Post  GM B-Body Forum on Thu May 18, 2017 5:24 pm

    How do you like the 3.08s?


    _________________
    1979 Caprice Sport Coupe, 400hp Vortec 350, Th350, GM 8.5 w/disc brakes, 3.90 gears Detroit Truetrac, 2.5" stainless duals w/ x-pipe, Dynomax race bullets.
    1984 Caprice Sedan, 305 motor, 700r4
    1978 Caprice Sedan, 305 motor, th350
    1993 L99 Caprice, 4.3 v8, 4l60 trans
    1972 Ford F-100, 302 windsor, c4 trans
    2001 BMW E46 330i, 3.0L
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    jimzagg
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    Re: Gear Ratio ?

    Post  jimzagg on Fri May 19, 2017 6:09 am

    Just went for a short drive. Seems much better. Gonna take the fuel tank out tonight and replace the sending unit. Then I'm going to do some carb tuning to get my mileage up. I'll keep you posted!
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    jimzagg
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    Re: Gear Ratio ?

    Post  jimzagg on Sat May 20, 2017 6:16 am

    Fuel tank out last night and replaced the sending unit. The one I removed was a replacement unit. The fuel gas still does not go past 1/4 full. Must be the gauge in the dash. Anyone have an idea where I might find a replacement?

      Current date/time is Thu Aug 24, 2017 2:50 am