06-24-2012, 04:12 PM | #1 |
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What gear ratio?
I have an 86 pickup that im putting 33in. tires with a 4 inch lift. Currently running 3.43 gears but im putting an auburn locker in. Should i go with 3.73 or stick with the 3.43? I have a ramjet 350 matted to a sm### (forgot the numbers) its the 3 speed with the granny gear.
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1986 GMC K15 4.3V6/SM465/NP205 will be converting to 5.3LS E-ROD/AA adapter/SM465/NP205 10 Bolt Axle Rebuild Tutorial: http://67-72chevytrucks.com/vboard/s...d.php?t=536415 |
06-24-2012, 04:47 PM | #2 |
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Re: What gear ratio?
Correction: Its actaully the 4 speed but i call it a 3 because the granny gear is pretty useless unless your towing.
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1986 GMC K15 4.3V6/SM465/NP205 will be converting to 5.3LS E-ROD/AA adapter/SM465/NP205 10 Bolt Axle Rebuild Tutorial: http://67-72chevytrucks.com/vboard/s...d.php?t=536415 |
06-24-2012, 06:59 PM | #3 |
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Re: What gear ratio?
go with 3.73
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06-24-2012, 07:01 PM | #4 |
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Re: What gear ratio?
i have the 3.42 gears and love it. i have stock tires tho but it i would guess i would say that it would feel like 3.23 on your truck
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1986 c20 "the hillbilly" 350 sm465 3.42gears 21mpg at 70mph 1985 k30 "the ice cream truck from hell" no rust az truck 197-8??? c30 "ramp truck" 454 1978 monte carlo 350 350th with 2.73 gears. no rust. sc car |
06-24-2012, 07:39 PM | #5 |
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Re: What gear ratio?
Would going with 3.73 help fuel economy any?
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1986 GMC K15 4.3V6/SM465/NP205 will be converting to 5.3LS E-ROD/AA adapter/SM465/NP205 10 Bolt Axle Rebuild Tutorial: http://67-72chevytrucks.com/vboard/s...d.php?t=536415 |
06-25-2012, 08:42 AM | #6 |
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Re: What gear ratio?
Your tranny is the sm465, and the 3.73 would hurt your fuel economy. I don't think putting the 33" tires is going to hurt you much, your "new" ratio if you leave the rear end how it is will be 3.22 with 33" tires, putting it to 3.73 would correct the gearing you lost from the tire swap though.....but with the 33" tires it would be like an over-drive, not quite as good, but would help your final drive ratio for going down the highway
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06-25-2012, 09:09 PM | #7 |
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Re: What gear ratio?
I definitely appreciate the input im going with an auburn locker 3.42 ratio.
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1986 GMC K15 4.3V6/SM465/NP205 will be converting to 5.3LS E-ROD/AA adapter/SM465/NP205 10 Bolt Axle Rebuild Tutorial: http://67-72chevytrucks.com/vboard/s...d.php?t=536415 |
06-26-2012, 03:38 AM | #8 |
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Re: What gear ratio?
remember when changing gear ratio on 4x4 trucks. you need to do both front and back same gear ratio . fyi.
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06-26-2012, 10:11 AM | #9 |
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Re: What gear ratio?
I put the same locker in my rear end about a year ago & its been good.. I was considering going 3.73 as well but when I factored in changing the front & the rear it started getting expensive, for me anyway as I didn't do it myself.. I'm running 33s too & gas mileage isnt too bad, but I've got overdrive & a 700r4 trans
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1987 Chev V10 Custom Deluxe 355tpi, 700R4, 3.42s in 10 bolt axles (for now!), new Auburn Posi in rear, 4" lift on 33s. |
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