G80 Conversion/Swap

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The Stig

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Hi I'm newer to the forums and I was wondering if it's possible to convert a open diff (non-G80) to a LSD or G80 and if so what's the cheapest and easiest way. My truck is a '97 K1500 with the 14-bolt 3.73 rear end if that makes a difference.
 

norad848

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If I'm not mistaken, 4x4 trucks should come with a G80/LSD from the factory. Check your glove box RPO sticker for the code "G80" to see if you already have one.
 

thz71

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Hi I'm newer to the forums and I was wondering if it's possible to convert a open diff (non-G80) to a LSD or G80 and if so what's the cheapest and easiest way. My truck is a '97 K1500 with the 14-bolt 3.73 rear end if that makes a difference.
Possible yes, worth while? No
If I'm not mistaken, 4x4 trucks should come with a G80/LSD from the factory. Check your glove box RPO sticker for the code "G80" to see if you already have one.
No they dont
 

TerryD

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Hi I'm newer to the forums and I was wondering if it's possible to convert a open diff (non-G80) to a LSD or G80 and if so what's the cheapest and easiest way. My truck is a '97 K1500 with the 14-bolt 3.73 rear end if that makes a difference.

Did you put the 14b under the truck or does it have a diesel?

Cheap is relative. I have a $100 mini-spool in my K5. It drags one tire around corners, doesn't turn on pavement very well in parking lots and puts plenty of stress on the chassis, but I don't have to worry about not pulling with both rear tires.

I want to put a $600 True-trac in my truck and Monte Carlo. No clutches to wear out, no special additives needed, no noise and as close to a true locker a you can get but not have one.

The middle point would be a drop in "lunchbox" locker like a Lock-rite. At about $300 they offer a good compromise and you don't have to reset the gears. It simply goes in where your spider gears are, only marginally more difficult than a differential fluid change.
 
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FastOrange

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G80 was Available in 4x4's and Z71's but wasnt standard for either, was a separate option.

14 bolt was available in 1500's regardless of engine, GM stopped putting 2500 on the 14-bolt SF trucks around 1995.
 

someotherguy

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G80 was Available in 4x4's and Z71's but wasnt standard for either, was a separate option.

14 bolt was available in 1500's regardless of engine, GM stopped putting 2500 on the 14-bolt SF trucks around 1995.

Not to sidetrack too much but a 14 bolt SF doesn't mean they're going to badge it a 2500, as there were 1500's with F44 suspension option that would have got the 14 bolt SF too - and still say 1500 on the doors and are of course marketed as a 1500. They'd get the extra leaf in the rear springs but it still was just shy of the same spring pack a 2500 light duty would get; thinner and shorter overload leaf. Had one of these myself - a 1994 Z71 with F44. Had of all things, 3.42's in the 14 bolt...and was optioned with the G80. As far as the timeframe for light duty 2500's, I'm kind of in agreement with you, the newest I think I've ever seen was a 1996. Do remember though that there are "real" (8 lug) 2500's that also got 14 bolt SF's, this also tended to be older models, but they were real 2500's all the way...just had the SF rear instead of FF.

If OP doesn't already have G80, he's miles ahead, because his open carrier can accept an aftermarket locker. If he's already got G80...need to swap to an open carrier in order to get anything else in there.

Seems like most people say the G80 isn't half bad as long as it's not the 10 bolt variety (a.k.a. Gov-Bomb) but I don't think I would go out of my way to swap one in; remember it was the low-bid unit that was cheap enough for GM to use it as original equipment. The aftermarket has better solutions.

Richard
 

TerryD

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Do remember though that there are "real" (8 lug) 2500's that also got 14 bolt SF's, this also tended to be older models, but they were real 2500's all the way...just had the SF rear instead of FF.

Richard

My 2000 OBS K2500 has the 8 lug SF14b and G80.

As for the gov lock, they work good as a traction aid when used properly. People mistake them for a means of spinning both rear wheels doing a burn out or launching like the old clutch type stuff. They don't work that way and treating them like that causes the catastrophic detonation that gave them the gov-bomb nick name.

We have one in our Suburban and had one in a 93 S10 Blazer and both gave excellent service. 220k miles on the Blazer when we sold it and 183k on our Suburban as we speak. Grandpa had one in a 76 C10 farm truck that worked great for about 25 years. We sold the axle to a guy who put it in a hot rod C10 and it lasted about a week before he blew pieces of it through the diff cover.
 

someotherguy

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That's why I said "tended" :gr_grin: the 8 lug 2500's were available both ways. For some reason it seems the older (1995-down) were more likely to see a SF; 1996-up tended to be FF. Neither are hard and fast rules.

100% agreed on the G80. They're not for playing. I think the 10 bolt unit though is significantly weaker due to the amount of "meat" in the carrier; according to an axle shop down here even the non-G80 10 bolt is weak once you get into the 30 spline variety that most GMT400's have except for the very first ones. He claims the early 28 spline units were stronger, at least in terms of the carrier.

Richard
 
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