The old longhorn is gettin a gear change - The 1947 - Present Chevrolet & GMC Truck Message Board Network

69 longhorn · 01-29-2005, 08:11 PM

Yup, as much fun as those 4.10's are, they are coming out in favor of the original 3.40 gear that were in the 12 bolt. i have a new pinion yolk for 1350 U joints, & also plan to upgrade the drive shaft, & add a set of Moser axles......lookin for tha "freeway flyer"

69L

1969 GMC · 01-29-2005, 09:10 PM

sweet...did it originally have a big block?

69 longhorn · 01-29-2005, 09:43 PM

No, it was originally a 350 powered truck.....it has run 2 455 Olds mills, & 1 425 cad , & a couple sb chevs over the last 20 yrs tho.... 69L

**kwmech** · 01-29-2005, 11:52 PM

In my experience big blocks really like the 3.5--3.4 ratios. My 68 GMC has a 3.54 ratio-factory. My 68 longhorn, I put a 14 bolt in with the 3.42 ratio. Both trucks are big blocks

69 longhorn · 01-30-2005, 12:33 AM

Yes, a mid 3's gear is perfect for a BB! I am running a 383 sb, with a 6spd trans behind it.....hoping that little stroker has enough "grunt" to pull a little taller gear. @ 29" tire, on the 3.40 gear , with .76 overdrive.....should set me really easy on the cruise range(3000 would be 100 mph).....that should keep up with the deisels running across Illinois

69L

01-29-2005, 08:11 PM	#1
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	The old longhorn is gettin a gear change Yup, as much fun as those 4.10's are, they are coming out in favor of the original 3.40 gear that were in the 12 bolt. i have a new pinion yolk for 1350 U joints, & also plan to upgrade the drive shaft, & add a set of Moser axles......lookin for tha "freeway flyer" 69L

01-29-2005, 09:10 PM	#2
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	sweet...did it originally have a big block? __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650

01-29-2005, 09:43 PM	#3
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	No, it was originally a 350 powered truck.....it has run 2 455 Olds mills, & 1 425 cad , & a couple sb chevs over the last 20 yrs tho.... 69L

01-29-2005, 11:52 PM	#4
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,596	In my experience big blocks really like the 3.5--3.4 ratios. My 68 GMC has a 3.54 ratio-factory. My 68 longhorn, I put a 14 bolt in with the 3.42 ratio. Both trucks are big blocks

01-30-2005, 12:33 AM	#5
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	Yes, a mid 3's gear is perfect for a BB! I am running a 383 sb, with a 6spd trans behind it.....hoping that little stroker has enough "grunt" to pull a little taller gear. @ 29" tire, on the 3.40 gear , with .76 overdrive.....should set me really easy on the cruise range(3000 would be 100 mph).....that should keep up with the deisels running across Illinois 69L



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