Really high gear ratio - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rolling · 10-09-2014, 10:39 AM

I installed a 76 front end into my 63 short box and was surprised to find the gear ratio was 2.73. It is listed as a factory option but just seems too high for a motor to operate in typical rpm range at 65 mph freeway speeds. I thought 3.73 would be more normal. Ideas?

**jeffahart** · 10-09-2014, 01:26 PM

This does not seem like a good surprise to me. Based on you may not have matching gearing in front and rear of your truck. Do not lock it in 4WD and drive it unless you are in some really slick slippery terrain.

Plus yes, those are generally half ton highway gears.

10-09-2014, 10:39 AM	#1
rolling Registered User Join Date: Aug 2014 Location: Fresno, ca Posts: 3	Really high gear ratio I installed a 76 front end into my 63 short box and was surprised to find the gear ratio was 2.73. It is listed as a factory option but just seems too high for a motor to operate in typical rpm range at 65 mph freeway speeds. I thought 3.73 would be more normal. Ideas?

10-09-2014, 01:26 PM	#2
jeffahart Senior Member Join Date: May 2012 Location: Scottsdale, AZ Posts: 1,907	Re: Really high gear ratio This does not seem like a good surprise to me. Based on you may not have matching gearing in front and rear of your truck. Do not lock it in 4WD and drive it unless you are in some really slick slippery terrain. Plus yes, those are generally half ton highway gears.



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