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3.90 gears = crap material?

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Old Jun 13, 2016 | 02:19 PM
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Default 3.90 gears = crap material?

Hi,
I just spoke with a gear shop who refuses to warranty 3.90 gear installs. He said they are made in China and recommended 3.73 or 4.10s. I've never heard this, but I do notice far fewer 3.90 gear owners out there. What is the consensus on these?
I'm considering this over my current 3.42s for my blown lt1 with a 12 bolt.
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Old Jun 13, 2016 | 02:31 PM
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Sounds like a bunch of crap to me
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Old Jun 13, 2016 | 02:42 PM
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Hmmm. I know the 3.90 isn't offered as widely as the 3.73s and 4.10s, however I haven't heard anything of the sort.

Frankly, I had always heard the 3.90s were stronger due to having fewer ring teeth (39/10 for the 3.90 versus 41/10 for the 4.11 and 41/11 for the 3.73).
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Old Jun 13, 2016 | 02:53 PM
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Originally Posted by HCI2000SS
Sounds like a bunch of crap to me

I would like to agree. Just that this shop has been around for quite some time and he seemed to speak with confidence on the topic.
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Old Jun 13, 2016 | 02:55 PM
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Originally Posted by Midnight02
Hmmm. I know the 3.90 isn't offered as widely as the 3.73s and 4.10s, however I haven't heard anything of the sort.

Frankly, I had always heard the 3.90s were stronger due to having fewer ring teeth (39/10 for the 3.90 versus 41/10 for the 4.11 and 41/11 for the 3.73).
Agreed on the teeth comment. The shop owner kept remarking about Motive and another name I can't recall that are only made in China and as unreliable.
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Old Jun 13, 2016 | 03:37 PM
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Ask him his source for info.
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Old Jun 13, 2016 | 03:48 PM
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I ran Motive 3.90s in my Mustang for 5 years, and never had a single issue. If I were you I'd call around to other reputable sources, and do your own research as well. I think you just might find that this shop may not know as much as you think on this matter
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Old Jun 13, 2016 | 03:52 PM
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I Picked Motive 3.90's over 4.10's for my 6-Speed and have never looked backed, And I did plenty of research.
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My 3.90's are going strong with many miles of abuse with drag radials, m6 amd stock 10 bolt with my stroker motor!
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Old Aug 23, 2016 | 04:08 PM
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Your shop is misinformed on motive gears.
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