The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > All 4x4 Tech & Off Roading

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 10-31-2009, 11:15 PM   #1
silver7
Registered User
 
silver7's Avatar
 
Join Date: Jul 2009
Location: High Point, NC
Posts: 613
Help - 4.10 or 4.56 gears?

I'm torn between going with 4.10 or 4.56 gears for my 12 inch rear end rebuild. I am working on a frame up restoration of a 71 custom C10 4x4 with 33" tires and a TH350 auto tranny. Any opinions or thoughts will be most appreciated.

Thanks,
Shawn
silver7 is offline   Reply With Quote
Old 10-31-2009, 11:16 PM   #2
silver7
Registered User
 
silver7's Avatar
 
Join Date: Jul 2009
Location: High Point, NC
Posts: 613
Re: Help - 4.10 or 4.56 gears?

Oh ya - it will be powered by a 383 stroker.
silver7 is offline   Reply With Quote
Old 10-31-2009, 11:40 PM   #3
vectorit
What?
 
vectorit's Avatar
 
Join Date: Jun 2007
Location: Southern California
Posts: 7,617
Re: Help - 4.10 or 4.56 gears?

4.56

Anything less, and your wasting your time and torque.

If you even mention/think/say gas mileage... Then, there is another sand box over there. But since you are talkin real gears, and at the same time talkin tire diameter and transmission. You already know what it takes.

Since you are going TH350, then you need to build it right to withstand the RPM. Plus, you will need to factor in the correct torque converter.

Sorry for sounding harsh, but I have been beat up in past threads. But since you posted something a little more specific, then you got my specific opinion about it.
__________________
Chris
1968 K20 Suburban
1972 K10 LWB PU
vectorit is offline   Reply With Quote
Old 11-01-2009, 12:11 AM   #4
Longhorn Man
its all about the +6 inches
 
Longhorn Man's Avatar
 
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
Re: Help - 4.10 or 4.56 gears?

i found this on the burb board.... putting it on the 4X4 board.
Longhorn Man is offline   Reply With Quote
Old 11-01-2009, 06:55 AM   #5
special-K
Special Order

 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,862
Re: Help - 4.10 or 4.56 gears?

I`d go with 4.10s.33s aren`t so big that they require deeper gears and 4.10s are deep enough.

The mags are all about making rock crawlers,which in reality isn`t what we drive for the most part.I fretted over gears on my`91 Suburban when lifting and going to 35s.The thing came with 4.10s and the mags had me convinced I needed to change to 4.56s.actually,i was mostly ignorant about the 4L80E and thought I needed to trick it into thinking it was still turning the same gears.I ound out the trans would be ok,so I went ahead with great results staying with 4.10s.The resulting ratio is right about 3.73 now and I can roll in o.d just fine as well as have all the bottom I need.If I had gone to 4.56s my ratio would have actually been right about 4.09:1.
Next,I did a lit and 35s on a`72 K/20 w/4.10s.It ran fine with that combo.
My`72 GMC has 33s and 3.54s.It has all the torque and power it needs.I can chirp second gear.It`s an automatic.
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed"

GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project)
GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

Last edited by special-K; 11-01-2009 at 12:19 PM.
special-K is offline   Reply With Quote
Old 11-01-2009, 07:45 AM   #6
Blazer1970
Registered User
 
Blazer1970's Avatar
 
Join Date: Dec 1999
Location: Old Mission, MI, USA
Posts: 2,510
Re: Help - 4.10 or 4.56 gears?

I agree with special-K - 4.10s with 33s.
__________________
Tim
Blazer1970 is offline   Reply With Quote
Old 11-01-2009, 08:10 AM   #7
vtblazer
Registered User
 
vtblazer's Avatar
 
Join Date: Oct 2003
Location: Central Vermont
Posts: 8,538
Re: Help - 4.10 or 4.56 gears?

Quote:
Originally Posted by Blazer1970 View Post
I agree with special-K - 4.10s with 33s.
X 3 on the 4:10's.

With a transmission ending at 1:1 for a final ratio, the 4:10/33's combo will still give you a 'drive-able' set up.

Expect to run around 3,000rpm's on the interstate at speed.

Last edited by vtblazer; 11-01-2009 at 08:11 AM.
vtblazer is offline   Reply With Quote
Old 11-01-2009, 10:59 AM   #8
Stocker
20' Daredevil (Ret)
 
Stocker's Avatar
 
Join Date: May 2003
Location: Jefferson State
Posts: 13,547
Re: Help - 4.10 or 4.56 gears?

Shawn, ya haven't told us (not in this thread, anyway) how you intend to use the truck, so it's kinda hard to say for sure what would be best for you.

For street use -- and especially if it will spend much time on highways -- I would opt for 4:10s. That's what I have in my K20 with 33s and I would certainly not go lower. Now if it's gonna be just around town or off road, 4:56s would be great.... but not for freeway use, not with a TH350.
__________________
- Mike -

1972 K20 LWB 350/350/205

RIP El Jay
Stocker is offline   Reply With Quote
Old 11-01-2009, 11:22 AM   #9
Mudder
Registered User
 
Mudder's Avatar
 
Join Date: Feb 2001
Location: East Central, MO
Posts: 11,336
Re: Help - 4.10 or 4.56 gears?

I am running 4.10's with my 35's/36's and my rpm range on the interstate is right around 3000. 383 stroker.
Mudder is offline   Reply With Quote
Old 11-01-2009, 11:52 AM   #10
kwmech
Senior Member
 
Join Date: Mar 2003
Location: Colfax-California
Posts: 8,428
Re: Help - 4.10 or 4.56 gears?

I'm running 4.56 with 33'' tires........BUT I've also got an overdrive that brings the final drive down to 3.31. Go with the 4.11
kwmech is offline   Reply With Quote
Old 11-02-2009, 06:45 PM   #11
Dooley
Registered User
 
Dooley's Avatar
 
Join Date: Mar 2005
Location: North Coast
Posts: 1,012
Re: Help - 4.10 or 4.56 gears?

4.10 gear.
Dooley is offline   Reply With Quote
Old 11-03-2009, 09:10 PM   #12
DieselEater
Registered User
 
DieselEater's Avatar
 
Join Date: Dec 2006
Location: Trinidad, Colorado
Posts: 642
Re: Help - 4.10 or 4.56 gears?

I'm with VECTORIT.........

Unless you are worried about fuel economy, or traveling on the high-way a lot, then there is no other option!

If you wanted fuel economy then you would have built a 305....

You will wish you had the steeper gears when you are pulling a trailer on a steep hill....

Surely your engine can handle being in the 3-4K RPM range, and occasionally hit 6K when having fun!



A............
__________________
69' 3/4 4X4
470ci BBC
700 HP....
D60/14bolt
205/465
http://profile.myspace.com/index.cfm...ndid=127691959

Last edited by DieselEater; 11-03-2009 at 09:14 PM. Reason: add to message...
DieselEater is offline   Reply With Quote
Old 11-03-2009, 09:38 PM   #13
silver7
Registered User
 
silver7's Avatar
 
Join Date: Jul 2009
Location: High Point, NC
Posts: 613
Re: Help - 4.10 or 4.56 gears?

All good replies guys, thanks. Sorry for not being more specific. My truck will be a weekly driver and may see a little time off road, but not much. I have a trailer I'll pull a little bit, but mostly I am building this thing to be a bad ass pick-up that looks, drives and sounds the part. I'm not concerned about gas mileage, just raw power and torque. 3K RPM at 60 is acceptable for me.
silver7 is offline   Reply With Quote
Old 11-04-2009, 08:04 AM   #14
vtblazer
Registered User
 
vtblazer's Avatar
 
Join Date: Oct 2003
Location: Central Vermont
Posts: 8,538
Re: Help - 4.10 or 4.56 gears?

Quote:
Originally Posted by Mudder View Post
I am running 4.10's with my 35's/36's and my rpm range on the interstate is right around 3000. 383 stroker.
That's interesting...

I ran 3k @ 65mph with 4:10's & 33's when I had my green blazer.

Clocked it many times via mile markers on the side of the interstate, thought for sure it was correct but we can't both be right...dunno.
vtblazer is offline   Reply With Quote
Old 11-04-2009, 09:36 AM   #15
Mudder
Registered User
 
Mudder's Avatar
 
Join Date: Feb 2001
Location: East Central, MO
Posts: 11,336
Re: Help - 4.10 or 4.56 gears?

I have the 203 TC and have no idea how fast I was running. I'm guessing around the 70 mark. Usually 2800-3000 but seems to be the 3000 more.
Mudder is offline   Reply With Quote
Old 11-04-2009, 11:53 PM   #16
special-K
Special Order

 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,862
Re: Help - 4.10 or 4.56 gears?

33s are not enough above stock to affect gearing much at all.If you can`t haul with 4.10s you have too much weight.With a 305 you might have wanted 4.56s to have the power.A 305 won`t save you gas when it comes to hauling.
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed"

GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project)
GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~
special-K is offline   Reply With Quote
Old 11-05-2009, 01:34 AM   #17
Stocker
20' Daredevil (Ret)
 
Stocker's Avatar
 
Join Date: May 2003
Location: Jefferson State
Posts: 13,547
Re: Help - 4.10 or 4.56 gears?

Quote:
Originally Posted by special-K View Post
33s are not enough above stock to affect gearing much at all.If you can`t haul with 4.10s you have too much weight.
Yes... when I bought my truck, I had 7.50-16 (stock size) Armstrong traction tires mounted, and they were exactly the same height (32.3") as my current 33/12.50-16.5s.
__________________
- Mike -

1972 K20 LWB 350/350/205

RIP El Jay
Stocker is offline   Reply With Quote
Old 11-05-2009, 01:46 AM   #18
2tons of fun
Account Suspended
 
Join Date: Jan 2009
Location: galt ca,
Posts: 749
Re: Help - 4.10 or 4.56 gears?

wtf is a 12" rear?

i am wasting rmp and power with 4.56 and 38"s, i cant image how slow it would be with 33"s.
2tons of fun is offline   Reply With Quote
Old 11-05-2009, 09:46 AM   #19
special-K
Special Order

 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,862
Re: Help - 4.10 or 4.56 gears?

Quote:
Originally Posted by 2tons of fun View Post
wtf is a 12" rear?
I totally missed that.Prolly cuz it`s so obvious he meant 12-bolt.

Heck,I haul with 33s/4.10s/even overdrive just fine.I`m talking a truck with a steel Reading work cap with side compartments full of tools,bed full of tools,ladder racks loaded with ladders,walkboards and pump jack poles,and a loaded trailer.I`ve weighed in at just under 10,000# before.and that wasn`t as loaded as I get.that`s with a partially loaded ladder rack and 1,000# of aluminum scrap.when I move from job to job I way a good bit over that.
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed"

GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project)
GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~
special-K is offline   Reply With Quote
Old 11-05-2009, 03:14 PM   #20
sailed2japan
Jonny
 
sailed2japan's Avatar
 
Join Date: Apr 2008
Location: Outside the Box, Austin,TX
Posts: 741
Re: Help - 4.10 or 4.56 gears?

I'm casting another vote for 4.10's. 33" is too short to mandate use of 4.56 gears.

I'm running 285/75r16's (33x11.5) and 3.73's. my truck is a disel, but even so it feels like it would be better with a taller tire or lower gear. Especially on the highway.
__________________
1966 C30, Cummins, stacks, and a flat bed in progress...
"Honor.....simply put,
A veteran - whether active duty, retired, national guard or reserve is someone who, at one time in his life, wrote a blank check made payable to 'The United States of America', for an amount of 'up to and including his life.' That is Honor, and there are way too many people in this country who no longer understand it."
-AEC Hundley USNR

Last edited by sailed2japan; 11-05-2009 at 03:16 PM.
sailed2japan is offline   Reply With Quote
Old 11-05-2009, 09:22 PM   #21
special-K
Special Order

 
special-K's Avatar
 
Join Date: Nov 2004
Location: Mt Airy, MD
Posts: 85,862
Re: Help - 4.10 or 4.56 gears?

That`s what I have,too...285/75s and a 195 hp diesel.At least,that`s the one I was just referring to in the prior thread.My Suburban has 4.10s/35s/135hp diesel and it does great hauling the same trailer and loaded with tools behind the second seat.
__________________
"BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed"

GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project)
GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling)
Tim

"Don't call me a redneck. I'm a rough cut country gentleman"

R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~
special-K is offline   Reply With Quote
Old 11-06-2009, 11:55 AM   #22
silver7
Registered User
 
silver7's Avatar
 
Join Date: Jul 2009
Location: High Point, NC
Posts: 613
Re: Help - 4.10 or 4.56 gears?

4.10 wins out. I can always go lower if needed. Thanks guys -great information.
silver7 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 01:33 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com