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Old 01-27-2009, 08:28 PM   #1
72c10lover16
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transmission and gearing questions

I have a 72 c-10 350 4b with an automatic trans behind it and i also just bought a 69 chevy c-10 straight 6 with a 4 speed. I was hoping to put the 4 speed in my 72 eventually but i was wondering how that would work out. some people have told me the gearing may be to low im not sure though.
Please let me know anything you know
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Old 01-27-2009, 10:14 PM   #2
mrein3
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Re: transmission and gearing questions

Both transmissions have the same final gear. 1:1. The only difference is that the auto will have some slip in the torque converter resulting in a slightly higher rpm on the highway when in high gear. That is why manuals get a bit better mileage than an auto with all other things on the truck equal.

The 4-speed may have a much lower 1st gear depending on the particular 4-speed you have.
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Old 01-28-2009, 07:59 AM   #3
72c10lover16
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Re: transmission and gearing questions

so the swap should work fine. does it matter what rear end i have in it.
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Old 01-28-2009, 09:34 AM   #4
mrein3
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Re: transmission and gearing questions

Quote:
Originally Posted by 72c10lover16 View Post
so the swap should work fine. does it matter what rear end i have in it.
Switching from an auto to a straight stick in your truck, without changing rear end gears or tire size, will drop your highway RPMs slightly. The slight drop will come from not having a torque converter slipping like you have in your auto right now.
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Old 01-28-2009, 05:06 PM   #5
72c10lover16
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Re: transmission and gearing questions

so when i go to swap them everything will function properly?
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Old 01-28-2009, 05:32 PM   #6
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Re: transmission and gearing questions

do lots of research on the swap such as changing crossmembers linkage etc// in my opinion a step backward
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Old 01-28-2009, 11:16 PM   #7
72c10lover16
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Re: transmission and gearing questions

is there anything else i need to know for this swap? what about driveshafts? i should be able to put the 69 one in my 72 right. thats after i switch the trannys.
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