What's everyone running for gears? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

feller · 10-31-2018, 08:04 PM

I've got a 4.8/4l60 combo going into a c10 long bed, curious as to what everyone else is doing for gears, I plan to dd it, and I burn wood so it will probably haul some, but nothing too serious. I want an all around performer out of this truck my first thought was 3.73s, with probably a 29 to no more than a 31 inch tire. Thanks in advance for the help

**mongocanfly** · 10-31-2018, 08:10 PM

3.73s should work good..I'm running 4.10s with 30"tire and od...I love the combo...
3.73s with a 30"tire at 65mph will turn around 1900rpm...

feller · 10-31-2018, 08:48 PM

That's what I was thinking, but math isn't my best subject, also I know my Cummins had 373s and when I had 33s it was pretty good milage, but then I put 35s on and it was a lot worse. Of course that truck would pull anything you wanted and I had it up to 110 more than once, it was a mean truck for sure. Thanks.

Macdaddy1 · 10-31-2018, 10:24 PM

I am also runnung 3.73's

**mongocanfly** · 10-31-2018, 10:34 PM

I cheated in math...haha...I use this rpm calc all the time to figure it out......down at the bottom of the page...
http://www.csgnetwork.com/multirpmcalc.html

feller · 10-31-2018, 11:43 PM

That calculator is awesome, 3.73+30 inch tire + .70 of, puts me at 1755 rpm, at 60 mph, that's right in the fuel mileage sweet spot. Thanks guys

BR3W CITY · 11-01-2018, 10:24 AM

3:73 and 28"s on mine.

sweetk30 · 11-01-2018, 01:52 PM

mines not on the road yet but 5.3/4l60-e/3.73/255/70/15=29.0 tire

60mph = 1800rpm
70mph = 2100rpm

OutlawDrifter · 11-01-2018, 03:15 PM

3.73 gears should be a good middle ground for economy/power. Don't be afraid to rev the little 4.8, the LS/LQ platform makes power higher in the curves than a standard SBC.

**Clyde65** · 11-01-2018, 09:00 PM

I have a 4.8/4l60e, 3.73:1 and 29” tires. The little 4.8 can burn the tires if I have the need. Sounds good and gets 20+mpg hey all day long.

Rich84 · 11-02-2018, 09:51 AM

Quote:

Originally Posted by sweetk30

mines not on the road yet but 5.3/4l60-e/3.73/255/70/15=29.0 tire

60mph = 1800rpm
70mph = 2100rpm

I have this set up with a 4l80..65 mph is about 2150 rpm's.

72MARIO · 11-02-2018, 06:19 PM

3:73 32" tire on my C20 6.0 4l80. Need 4:10 or 4:56 for the work it does. To low of rpm alway dropping into 3rd and 2nd climbing hills.
My suburban is 27" tire 3:42 pulls way better but still would like 3:73 or 4:10 in it. Need to target 2200 rpm at 62 mph for my liking.

feller · 11-02-2018, 08:47 PM

Clyde 65, that's what I wanted to hear, thank you all for answering, with real world results

crazy longhorn · 11-04-2018, 05:29 PM

I agree a 3.73, on a 29 tire....good mix! Longhorn

10-31-2018, 08:04 PM	#1
feller Registered User Join Date: Feb 2011 Location: madison, IN. Posts: 484	What's everyone running for gears? I've got a 4.8/4l60 combo going into a c10 long bed, curious as to what everyone else is doing for gears, I plan to dd it, and I burn wood so it will probably haul some, but nothing too serious. I want an all around performer out of this truck my first thought was 3.73s, with probably a 29 to no more than a 31 inch tire. Thanks in advance for the help

10-31-2018, 08:10 PM	#2
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,670	Re: What's everyone running for gears? 3.73s should work good..I'm running 4.10s with 30"tire and od...I love the combo... 3.73s with a 30"tire at 65mph will turn around 1900rpm... __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

10-31-2018, 08:48 PM	#3
feller Registered User Join Date: Feb 2011 Location: madison, IN. Posts: 484	Re: What's everyone running for gears? That's what I was thinking, but math isn't my best subject, also I know my Cummins had 373s and when I had 33s it was pretty good milage, but then I put 35s on and it was a lot worse. Of course that truck would pull anything you wanted and I had it up to 110 more than once, it was a mean truck for sure. Thanks.

10-31-2018, 10:24 PM	#4
Macdaddy1 Registered User Join Date: Dec 2017 Location: Niceville Florida Posts: 347	Re: What's everyone running for gears? I am also runnung 3.73's

10-31-2018, 10:34 PM	#5
mongocanfly Post Whore Join Date: May 2015 Location: Alabama Posts: 14,670	Re: What's everyone running for gears? I cheated in math...haha...I use this rpm calc all the time to figure it out......down at the bottom of the page... http://www.csgnetwork.com/multirpmcalc.html __________________ Mongo...aka Greg RIP Dad RIP Jesse 1981 C30 LQ9 NV4500..http://67-72chevytrucks.com/vboard/s...d.php?t=753598 Mongos AD- LS3 TR6060...http://67-72chevytrucks.com/vboard/s...34#post8522334 Columbus..the 1957 IH 4x4...http://67-72chevytrucks.com/vboard/s...63#post8082563 2023 Chevy Z71..daily driver

10-31-2018, 11:43 PM	#6
feller Registered User Join Date: Feb 2011 Location: madison, IN. Posts: 484	Re: What's everyone running for gears? That calculator is awesome, 3.73+30 inch tire + .70 of, puts me at 1755 rpm, at 60 mph, that's right in the fuel mileage sweet spot. Thanks guys

11-01-2018, 10:24 AM	#7
BR3W CITY meowMEOWmeowMEOW Join Date: Sep 2009 Location: MKE WI Posts: 7,128	Re: What's everyone running for gears? 3:73 and 28"s on mine. __________________ *'66 Short Step / SD Tuned / Big Cam LQ4 / Backhalfed /Built 4l80e / #REBUILDEVERYTHING* MY BUILD THE H8RDCPTR //\\ MY YOUTUBE CHANNEL REV J HD

11-01-2018, 01:52 PM	#8
sweetk30 Registered User Join Date: May 2012 Location: horseheads,ny rust belt Posts: 2,794	Re: What's everyone running for gears? mines not on the road yet but 5.3/4l60-e/3.73/255/70/15=29.0 tire 60mph = 1800rpm 70mph = 2100rpm __________________ 77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great.

11-01-2018, 03:15 PM	#9
OutlawDrifter Registered User Join Date: Aug 2012 Location: Northeast KS Posts: 1,788	Re: What's everyone running for gears? 3.73 gears should be a good middle ground for economy/power. Don't be afraid to rev the little 4.8, the LS/LQ platform makes power higher in the curves than a standard SBC. __________________ 1999 GMC Suburban K2500 SLT, 454/4L80E 1991 Z/28, 6.0L/T56 1949 GMC 250, S10 Frame, 6.0L/4L80E Instagram @aceshighspeedshop

11-01-2018, 09:00 PM	#10
Clyde65 1965 Chevy C10, 2005 4.8L/4l60 Join Date: Aug 2004 Location: DFW Texas Posts: 8,546	Re: What's everyone running for gears? I have a 4.8/4l60e, 3.73:1 and 29” tires. The little 4.8 can burn the tires if I have the need. Sounds good and gets 20+mpg hey all day long. __________________ Clyde65 Rebuild of Clyde http://67-72chevytrucks.com/vboard/s...84#post8338184 69 Aristocrat Lo Liner build http://67-72chevytrucks.com/vboard/s...84#post7561684 *support our troops!*

11-02-2018, 06:19 PM	#12
72MARIO Registered User Join Date: Nov 2000 Location: Huntsville Ontario Canada Posts: 4,051	Re: What's everyone running for gears? 3:73 32" tire on my C20 6.0 4l80. Need 4:10 or 4:56 for the work it does. To low of rpm alway dropping into 3rd and 2nd climbing hills. My suburban is 27" tire 3:42 pulls way better but still would like 3:73 or 4:10 in it. Need to target 2200 rpm at 62 mph for my liking. __________________ 1968 Suburban numbers matching all original truck now equipped with 6.0/4L80 on Accuair http://67-72chevytrucks.com/vboard/s...d.php?t=625017 1967 C/20 6.0/4L80 Roofing Truck 1990 V2500 Suburban "Plow Truck" 2005 TAHOE DD

11-02-2018, 08:47 PM	#13
feller Registered User Join Date: Feb 2011 Location: madison, IN. Posts: 484	Re: What's everyone running for gears? Clyde 65, that's what I wanted to hear, thank you all for answering, with real world results

11-04-2018, 05:29 PM	#14
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	Re: What's everyone running for gears? I agree a 3.73, on a 29 tire....good mix! Longhorn __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....



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