The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - C30 dually rear diff gearing options help please

Big Moose · 12-30-2021, 12:38 AM

I had 4.56s and went to 4.10s.when the bearings went kaput. didn't make a big difference in fuel mileage, maybe 0.5 mpg highway. I have a 6L LS/4L80 in it. it originally had a 350/th350 and it was screaming at highway speeds.

12-30-2021, 12:38 AM	#5
Big Moose Registered User Join Date: Dec 2018 Location: Alberta Posts: 71	Re: C30 dually rear diff gearing options help please I had 4.56s and went to 4.10s.when the bearings went kaput. didn't make a big difference in fuel mileage, maybe 0.5 mpg highway. I have a 6L LS/4L80 in it. it originally had a 350/th350 and it was screaming at highway speeds.