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#1 |
Registered User
Join Date: Jan 2009
Location: Denison, Texas
Posts: 245
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speedo gears
I have a TH350 with a 3.73 rear end and 275/60/15 tires (28") in my 71 GMC the problem is I donthave the drive or driven gear for the speedo and can seem to find out what gear combo i need to go with.
Can anyone pointme in the right direction? Last edited by Longhorn Man; 02-24-2009 at 06:42 AM. |
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#2 |
Registered User
Join Date: Mar 2003
Location: Uvalde, Tx
Posts: 407
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Re: speedo gears
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1969 C/10 Longbed undergoing rebuild. Old Chevy's Never Die, They Just Rust Around The Edges |
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#3 |
LET'S GO...MOUNTAINEERS
Join Date: Oct 2007
Location: Williamstown, WV
Posts: 339
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Re: speedo gears
It will be the the purple gear with 10 teeth. I just did the same swap on my 350/TH350 with 3.73s.
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72 SWB/Step Last edited by westbrookw; 02-23-2009 at 03:30 PM. |
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#4 |
LET'S GO...MOUNTAINEERS
Join Date: Oct 2007
Location: Williamstown, WV
Posts: 339
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Re: speedo gears
Actually, let me go to the house and I will look at it. But I am pretty sure that is what I used. The one you pulled out should have been black with 8 teeth on 3.08 gears.
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72 SWB/Step |
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#5 |
Registered User
Join Date: Jan 2009
Location: Denison, Texas
Posts: 245
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Re: speedo gears
Ok I have a spare purple gear for the trans do you know what gear you used for the speedo cable?
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#6 |
LET'S GO...MOUNTAINEERS
Join Date: Oct 2007
Location: Williamstown, WV
Posts: 339
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Re: speedo gears
The driven gear I took out of the speedo sender was an 18 tooth gear, I believe the color was supposed to be purple. A friend of mine and I did alot of research and found that I need a 22 tooth driven gear. The drive gear inside of my trans is the 8 tooth orange gear. Here is where we found real good info. http://www.tciauto.com/Products/Tech...eedo_gears.asp. That is all I have. I have no idea as to weather mine is accurate due to the fact I have my speedo cable in the mail. That should get you close by our calculations.
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72 SWB/Step |
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#7 |
Registered User
Join Date: Jan 2009
Location: Denison, Texas
Posts: 245
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Re: speedo gears
thanks for the help i'll check it out.
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#8 |
LET'S GO...MOUNTAINEERS
Join Date: Oct 2007
Location: Williamstown, WV
Posts: 339
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Re: speedo gears
It is pretty accurate. I was rolling at 55 with a buddy beside me telling me he was at 55. We ran them all the way up to 70 reading the same. I guess this would have to be your combo. Good luck. Glad I could help you in anyway.
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72 SWB/Step |
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#9 |
Registered User
Join Date: Mar 2003
Location: Uvalde, Tx
Posts: 407
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Re: speedo gears
Glad to hear you got it figured out.
__________________
1969 C/10 Longbed undergoing rebuild. Old Chevy's Never Die, They Just Rust Around The Edges |
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