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#1 |
GobbleStalker Calls
![]() Join Date: Aug 2010
Location: Port Hope, Ontario
Posts: 653
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Rear end help.
I just found out my truck is not posi and has 3.07 gears. I want ot make it a posi and am pretty sure I will want to change the gears to 3.55 ot 3.73's. What is the spline on these trucks. Can I put a 12 bolt camero gears and posi in or will they not match up?
Thanks Kev |
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#2 |
Registered User
Join Date: Mar 2003
Location: San Francisco, CA USA
Posts: 2,454
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Re: Rear end help.
The 12 bolt car R&P can not be used in the truck rear. You will need gears made specifically for the truck. The truck shafts (65-up) have 30 splines.
http://tomsdifferentials.com/catalog.asp?pg=10 Ray |
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#3 |
Six in a row makes it go...
![]() Join Date: Mar 2009
Location: Vacationland: Maine
Posts: 1,346
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Re: Rear end help.
Have you ever set-up a rear before? Setting the pinion depth usually requires special tools...
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67 C20 long step resto: http://67-72chevytrucks.com/vboard/s...d.php?t=342086 66 C10 long step build: http://67-72chevytrucks.com/vboard/s...=1#post3814790 CT to Alaska in a 67 C10: http://67-72chevytrucks.com/vboard/s...d.php?t=399224 “The height of sophistication is simplicity." - Clare Boothe Luce |
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#4 |
Senior Member
Join Date: Jan 2003
Location: daytonabeach
Posts: 22,956
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Re: Rear end help.
if you buy the parts//posi,gears,bearings shims seals etc it's right around the $800mark
to me investing that much money it's worth the extra to have it installed by a pro for the few extra hundred another option is to look for a 40year old junkyard piece and take your chances with a well worn $300-$400 piece
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71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY |
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#5 | |
just can't cover up my redneck
Join Date: May 2004
Location: Columbus OH
Posts: 11,414
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Re: Rear end help.
Once again, cdowns is on it. "Pay a Professional"
Setting up a rear end is a very precise thing. It has to be done exactly right or it will fail quickly.
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#6 |
GobbleStalker Calls
![]() Join Date: Aug 2010
Location: Port Hope, Ontario
Posts: 653
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Re: Rear end help.
I would not be doing htis myself. Beyond my capabilities. Thanks
Kev |
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#7 |
Six in a row makes it go...
![]() Join Date: Mar 2009
Location: Vacationland: Maine
Posts: 1,346
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Re: Rear end help.
Well then - raycow is right, you can't use car parts in the truck rears. There's plenty of truck 12-bolt gears and posi carriers available.
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67 C20 long step resto: http://67-72chevytrucks.com/vboard/s...d.php?t=342086 66 C10 long step build: http://67-72chevytrucks.com/vboard/s...=1#post3814790 CT to Alaska in a 67 C10: http://67-72chevytrucks.com/vboard/s...d.php?t=399224 “The height of sophistication is simplicity." - Clare Boothe Luce |
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#8 |
GobbleStalker Calls
![]() Join Date: Aug 2010
Location: Port Hope, Ontario
Posts: 653
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Re: Rear end help.
So now the question. I am building the 350 to be between 300 and 350 hp. Have a 350Turbo trans. Should I stay with the 3.07 gears and just put a posi in or change the gears. I am afraid if I go to 3.73 I will rev around 4000rpm on the highway. Anyone have experience with this set up? I don't want the truck to be a dog of the line either.
Kevin |
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#9 | |
just can't cover up my redneck
Join Date: May 2004
Location: Columbus OH
Posts: 11,414
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Re: Rear end help.
It depends upon what you consider "highway speed" to be, and how much of the time you are driving that speed.
__________________
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#10 |
GobbleStalker Calls
![]() Join Date: Aug 2010
Location: Port Hope, Ontario
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Re: Rear end help.
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#11 |
Registered User
Join Date: Apr 2000
Location: Bonne Terre, Mo
Posts: 3,005
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Re: Rear end help.
I'm going to make a wild guess...350 turbo..307 rear..60-62 MPH Maybe some where around 5500-5900 rpm?
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#12 |
Registered User
Join Date: Jan 2008
Location: Post Falls, Idaho
Posts: 606
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Re: Rear end help.
my truck 350 motor,turbo 350,3.07 gears at 60mph = 2000 rpm. i had a 66 chevelle 396,4speed,373 gears at 60mph =3000 rpm.
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#13 |
Registered User
![]() Join Date: Jan 2007
Location: tennessee
Posts: 159
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Re: Rear end help.
If your gong with all new stuff, go with a 3.42 gear set and good differential.
Also like it has been previously said, let a pro put the rear end together.You will save money in the long run. ![]() |
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#14 |
Gone to greener pastures
![]() Join Date: May 2007
Location: Gateway to the Delta
Posts: 7,354
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Re: Rear end help.
I have 2 trucks, both with 4.10:1 rear gears.
Both turn about 3000-3100 RPM at 65 MPH.
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#15 |
Registered User
Join Date: Jan 2007
Location: Sonoma, CA
Posts: 521
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Re: Rear end help.
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#16 |
Registered User
Join Date: Mar 2005
Location: 10-Uh-See
Posts: 5,609
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Re: Rear end help.
My 350/TH350/3.73 combo with 28" tires runs about 3300 at 65. 3.07 gears are more highway friendly. I say go with the 3.42 gear and have a compromise of 3.73 and 3.07 gears.
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#17 |
Six in a row makes it go...
![]() Join Date: Mar 2009
Location: Vacationland: Maine
Posts: 1,346
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Re: Rear end help.
I like this compromise if you're gonna go with the TH350.
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67 C20 long step resto: http://67-72chevytrucks.com/vboard/s...d.php?t=342086 66 C10 long step build: http://67-72chevytrucks.com/vboard/s...=1#post3814790 CT to Alaska in a 67 C10: http://67-72chevytrucks.com/vboard/s...d.php?t=399224 “The height of sophistication is simplicity." - Clare Boothe Luce |
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