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#1 |
Simple? What's simple?
![]() Join Date: Apr 2007
Location: Southeast CT
Posts: 1,472
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Standard axle ratios?
I've been trying to figure out the axle ratio in my '69 K-10, without much luck. No tag on the diff and I can't see (too much rust scaling) the stamped code on the axle tubes.
That said, it's a pretty basic truck and doesn't have a SPID entry for rear end ratio. So, what should be the standard rear end for my truck? It's an early '69 (Dec. 68 build date / motor code), 4x4, has a 307 2bbl, SM465, Rockwell T221 and the rear is a 12 bolt. Given the way it drives on the highway I'm guessing 4.10, but not sure I could tell between 4.10 and 3.73 by ear (no tach).
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CURRENT '50 GMC 100 shortbed Gen IV 4.8 LS - 4L65E (Secret truck, Shhh!!!) Build '63 Buick Wildcat Coupe 401ci Nailhead (Very much in pieces) Photos '66 Impala SS convertible 327-QJet-glide (4 speed swap one of these days...) Photos '69 CST/10 4x4 SWB Stepper 350 2bbl - NV4500/NP241C (Broken Truck!) '72 Sierra Grande 2WD LWB fleetside 350-TH350 Refresh '99 K2500 Silverado RCLB 5.7 Vortec - NV4500/NP241C (Daily) '99 K2500 Suburban 7.4 Vortec - NV4500/NP246 (still working out the bugs) SOLD '71 Custom/10 2WD LWB fleetside - '72 GMC K/3500 Dually (Sold to redryder) |
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#2 |
Registered User
Join Date: Jan 2008
Location: west richland WA
Posts: 61
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Re: Standard axle ratios?
you can take your diff cover off and on your ring gear there will be 2 numbers
you divide the big number by the little number and it will give you your ratio
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67' chevy k10 350 sm420 |
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#3 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Re: Standard axle ratios?
I am not all that educated on the 4x4s, but I would think 3.73
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#4 |
Registered User
Join Date: Dec 2007
Location: Santa Maria, Ca.
Posts: 1,423
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Re: Standard axle ratios?
My 69 4x4 had 4.09 in front and 4.10 in back but I have no way of knowing if it came factory that way. I have since changed the rear to a 73 14 bolt.
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69 Chevy 4x4 383 Power ![]() |
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#5 |
6>8 Plugless........
![]() Join Date: Sep 2007
Location: Prairie City, Ia
Posts: 17,140
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Re: Standard axle ratios?
I have seen a lot of 4 speed K10's with 3.07's in this era for some reason.
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Ryan 1972 Chevy Longhorn K30 Cheyenne Super, 359 Inline 6 cylinder, Auto Trans, Tilt, Diesel Tach/Vach, Buckets, Rare Rear 4-link and air ride option Build Thread 1972 GMC Sierra Grande Longhorn 4x4 1972 Chevy Cheyenne Super K20 Long Step side tilt, tach, tow hooks, AC, 350 4 speed 1972 C10 Suburban Custom Deluxe 1969 Chevy milk truck 1971 Camaro RS 5.3 BTR STG3 Cam Super T10 1940 Ford 354 Hemi 46RH Ford 9" on air ride huge project Tired of spark plugs? Check this out. |
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#6 |
Registered User
Join Date: Feb 2007
Location: west coast
Posts: 3,372
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Re: Standard axle ratios?
If no ratio on the SPID, it has the standard ratio of 3.73. The standard V8 should not be on the SPID either. The only powertrain option on your SPID should be the M20 4 speed.
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#7 |
Registered User
Join Date: Dec 1999
Location: Old Mission, MI, USA
Posts: 2,510
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Re: Standard axle ratios?
If it came with a 350, it came with 3.07 gears. If it came with a 307 or a 250 it came with 3.73 gears.
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Tim |
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#8 | |
Simple? What's simple?
![]() Join Date: Apr 2007
Location: Southeast CT
Posts: 1,472
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Re: Standard axle ratios?
Quote:
![]() Thanks much for the information guys.
__________________
CURRENT '50 GMC 100 shortbed Gen IV 4.8 LS - 4L65E (Secret truck, Shhh!!!) Build '63 Buick Wildcat Coupe 401ci Nailhead (Very much in pieces) Photos '66 Impala SS convertible 327-QJet-glide (4 speed swap one of these days...) Photos '69 CST/10 4x4 SWB Stepper 350 2bbl - NV4500/NP241C (Broken Truck!) '72 Sierra Grande 2WD LWB fleetside 350-TH350 Refresh '99 K2500 Silverado RCLB 5.7 Vortec - NV4500/NP241C (Daily) '99 K2500 Suburban 7.4 Vortec - NV4500/NP246 (still working out the bugs) SOLD '71 Custom/10 2WD LWB fleetside - '72 GMC K/3500 Dually (Sold to redryder) Last edited by JJorgensen52; 02-07-2010 at 11:49 AM. |
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