front axle is wider than the rear? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

1968k10blue · 09-14-2013, 02:27 AM

IIs it normal for a 68 k10 to have a wider front axle than the rear? On a side note, is there anyone here that might want to trade differential gears? I know it's the wrong thread but I have 4.11a on both front and rear and if anyone wants to trade for a set of 3.73s that would be great. Mine runs a little too high RPMs at speed since mine will be a dd and I want a little better gas mileage without sacrificing too much torque.
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zeeklu · 09-14-2013, 05:11 AM

Yes, they're a little wider. Chris

geezer#99 · 09-14-2013, 06:59 AM

LOwer gears don't always equal better mileage!
Try the poorman's gear change. Put on some tires that are 2" taller. That'll give you the equivalent of 3.73's.
Four used tires to test with is always way cheaper than swapping two sets of gears.

Chrome8 · 09-14-2013, 08:33 AM

Randy's ring and pinion has a calculator for RPM at a given speed in relation to tire size. It comes in handy when picking out tire sizes. There are other calculators on his site as well. Keep in mind your speedometer will be off if you increase the tire size or change the gear ratio. The front is supposed to be wider than the rear, I believe it was 1970 when both the front and rear got about 1.5 in wider. It is popular to swap a 73-up front axle into these trucks to achieve disk brakes and an open knuckle front, so if that was done one time or another the front may look disproportionally wide because like I said they are wider past 1970 (I think that's the right year).

http://www.ringpinion.com/Calculators/Calc_RPM.aspx

1968k10blue · 09-14-2013, 10:27 AM

Thanks for all the replies! I already have 31 inch tires, I Don exactly have the clearance for bigger tires but in my case when I run 2500 rpm at 55 mph 3.73s would give me just enough rpm to spare at high speeds to actually improve mileage (not that much of course) but it will help.
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cdowns · 09-14-2013, 10:53 AM

Quote:

Originally Posted by geezer#99

LOwer gears don't always equal better mileage!
Try the poorman's gear change. Put on some tires that are 2" taller. That'll give you the equivalent of 3.73's.
Four used tires to test with is always way cheaper than swapping two sets of gears.

373 are higher than a 411 not lower

09-14-2013, 02:27 AM	#1
1968k10blue Registered User Join Date: Aug 2013 Location: Mahtomedi, Minnesota Posts: 335	front axle is wider than the rear? IIs it normal for a 68 k10 to have a wider front axle than the rear? On a side note, is there anyone here that might want to trade differential gears? I know it's the wrong thread but I have 4.11a on both front and rear and if anyone wants to trade for a set of 3.73s that would be great. Mine runs a little too high RPMs at speed since mine will be a dd and I want a little better gas mileage without sacrificing too much torque. Posted via Mobile Device

09-14-2013, 05:11 AM	#2
zeeklu Registered User Join Date: Dec 1999 Location: Northwest NJ Posts: 746	Re: front axle is wider than the rear? Yes, they're a little wider. Chris

09-14-2013, 06:59 AM	#3
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,532	Re: front axle is wider than the rear? LOwer gears don't always equal better mileage! Try the poorman's gear change. Put on some tires that are 2" taller. That'll give you the equivalent of 3.73's. Four used tires to test with is always way cheaper than swapping two sets of gears.

09-14-2013, 08:33 AM	#4
Chrome8 Registered User Join Date: Nov 2005 Location: Park Rapids, MN Posts: 288	Re: front axle is wider than the rear? Randy's ring and pinion has a calculator for RPM at a given speed in relation to tire size. It comes in handy when picking out tire sizes. There are other calculators on his site as well. Keep in mind your speedometer will be off if you increase the tire size or change the gear ratio. The front is supposed to be wider than the rear, I believe it was 1970 when both the front and rear got about 1.5 in wider. It is popular to swap a 73-up front axle into these trucks to achieve disk brakes and an open knuckle front, so if that was done one time or another the front may look disproportionally wide because like I said they are wider past 1970 (I think that's the right year). http://www.ringpinion.com/Calculators/Calc_RPM.aspx __________________ 1969 K20 not running, complete but rusty with wrecker boom and push bumper 1969 GMC C20 un-molested rust free original paint "a 4 eyed girl named 'Tina" 1971 Chev K20 4X4 Box Delete Commercial Truck Flatbed "Choose a job you love, and you will never have to work a day in your life." Confucius

09-14-2013, 10:27 AM	#5
1968k10blue Registered User Join Date: Aug 2013 Location: Mahtomedi, Minnesota Posts: 335	Re: front axle is wider than the rear? Thanks for all the replies! I already have 31 inch tires, I Don exactly have the clearance for bigger tires but in my case when I run 2500 rpm at 55 mph 3.73s would give me just enough rpm to spare at high speeds to actually improve mileage (not that much of course) but it will help. Posted via Mobile Device



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