The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

**Ironangel** · 10-24-2018, 07:59 AM

Baime, thats a Dana 60 in your pic, KEEP IT! Dont let anyone who dont know what it is touch it! There is no such thing as a "T400R4"...Need to determine what gearing is in it now by pulling the cover and getting the numbers off the ring gear. You will also be able to determine what carrier you have at the same time. The Dana 60 only goes as high as 3:55 and as low as 7:17 with the carrier break at 4:10/4:56. Nows the time to ask yourself what exactly are your plans for your 3/4 ton Jimmy? Are you pulling heavy trailers and hauling heavy loads? Do you have a $3K to invest in a gear set, a posi or locker, and a questionable 700r4? Not trying to rain on your parade but transforming a 71 3/4 ton GMC into gas friendly daily driver is an expensive endeavor. The least expensive way out is a new 3:55 gear set and taller 16" tires and wheels...My daily driver has 3:73 gears turning 31" 275/70R-16's with a built 350 Turbo to pull a tandem trailer with another 4000lb truck on it. If mileage is paramount, then you cant afford to drive these old trucks..."Just Sayin"

10-24-2018, 07:59 AM	#23
Ironangel Senior Member Join Date: Feb 2010 Location: Falls City, Nebraska "100 Miles From Nowhere" Posts: 2,219	Re: 1971 GMC C2500 rear end questions Baime, thats a Dana 60 in your pic, KEEP IT! Dont let anyone who dont know what it is touch it! There is no such thing as a "T400R4"...Need to determine what gearing is in it now by pulling the cover and getting the numbers off the ring gear. You will also be able to determine what carrier you have at the same time. The Dana 60 only goes as high as 3:55 and as low as 7:17 with the carrier break at 4:10/4:56. Nows the time to ask yourself what exactly are your plans for your 3/4 ton Jimmy? Are you pulling heavy trailers and hauling heavy loads? Do you have a $3K to invest in a gear set, a posi or locker, and a questionable 700r4? Not trying to rain on your parade but transforming a 71 3/4 ton GMC into gas friendly daily driver is an expensive endeavor. The least expensive way out is a new 3:55 gear set and taller 16" tires and wheels...My daily driver has 3:73 gears turning 31" 275/70R-16's with a built 350 Turbo to pull a tandem trailer with another 4000lb truck on it. If mileage is paramount, then you cant afford to drive these old trucks..."Just Sayin" __________________ Michael of the clan Hill, "Two Seventy Two's" 71 1-ton Dually 350 4-Speed 71 C/50 Grain Truck, 350 Split-Axle 4-Speed 02 3/4 ton Express 14 Indian Chief Vintage 1952 Ford 8N, "Only Ford Allowed On The Property" "Be American, Buy American"