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Red....USA1 is right...I understand the the rear is a recycled Vega part...However, I found this past thread on the subject for you:

http://www.trifive.com/forums/showthread.php?t=126355

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The vega rear may fit but it aint too strong. I had a 72 vega GT. Add a hot buick V6 with a shift kitted turbo 350. My personalized plate was 6K RPM. shift to 2nd anything and sometimes including 6000 RPM. and the rear end was toast.
 
There are several of us that build cruisers, not race cars. I have had great luck with mine. Around my area there are 5 of us that use them in Tri fives. 1 56, 1 57, 1 57 wagon(mine) and 1 57 nomad. We have have had none break. Every time this comes up it turns in to a bashing of the S-10 rears. Sure others may better better suited for others but the S-10 rears will work with little modifications. I personally have yet to have any problems but to each his own.
 
I need some education then....I'm sitting here with a perfectly fine, original, 8.2 rear end in my car....Why should I swap it out for a 7.5, S-10 rear, even if it was given to me?
 
I didn't say an S-10 was better. The man ask a question and I answered. Keep what you have. Mine was not the gearing I desired and the end result was four wheel disks.I am happy with the change but each owner has their own desire on what to expect from their car builds. It worked for me. Mine is no better than anyone's nor my opinion carry more weight. I'm not trying to educate you on anything as I expect you already know more than I do. No disrespect intended.
 
I am sometimes the source of useless info, so here we go. When Chevy introduced the third gen Camaro in 1982 the 350 was dropped because it was too much for the 7.5 Camaro rear. When the 350 was reintroduced in IROCs Z28s in 1987 they got a stronger 7.75 Borg Warner built non C-clip rear. This is the engineers at GM speaking not me.
 
I am sometimes the source of useless info, so here we go. When Chevy introduced the third gen Camaro in 1982 the 350 was dropped because it was too much for the 7.5 Camaro rear. When the 350 was reintroduced in IROCs Z28s in 1987 they got a stronger 7.75 Borg Warner built non C-clip rear. This is the engineers at GM speaking not me.
Some would argue that although the BW was a small upgrade it was mostly only found in the Z`s and the Birds.
 
Not many of the BW 9 bolts come up for sale and parts for them.
I think you missed my point, I agree they were rare and not supported in aftermarket. I would never advocate using one in other than its OEM application. My point was the engineers at GM felt an upgrade was necessary to the 7.5 before even a mild 350 was offered in a Camaro.

My brother in law bought one of the first Z28s produced with a TPI 350 and still has it. A friend of mine and his son put a 383 in a 350 Iroc with Vortec heads and it runs 13 flat with 26 tall Mickey Thompson slicks. I have a little first hand knowledge of these rears. The thing that surprised me the most is no c-clips.
 
I have a little first hand knowledge of these rears. The thing that surprised me the most is no c-clips.
So, Mark....If they have no C-clips, are the axles held in the same way as they are on our TriFives then?
 
So, Mark....If they have no C-clips, are the axles held in the same way as they are on our TriFives then?
Yes, I told my buddy we should replace axle bearings and inspect the rest before we went to track. When we pulled the cover I got a surprise. FYI, it is standing procedure at my house to replace rear wheel bearings on C-clip rear ends every 100,000 miles. It is cheaper than chewing up axles.

However they use tapered roller bearings instead of ball.
 
I think you missed my point, I agree they were rare and not supported in aftermarket. I would never advocate using one in other than its OEM application. My point was the engineers at GM felt an upgrade was necessary to the 7.5 before even a mild 350 was offered in a Camaro.

My brother in law bought one of the first Z28s produced with a TPI 350 and still has it. A friend of mine and his son put a 383 in a 350 Iroc with Vortec heads and it runs 13 flat with 26 tall Mickey Thompson slicks. I have a little first hand knowledge of these rears. The thing that surprised me the most is no c-clips.
I got your point and a portion of the point is GM knew the 7.5`s were weak and probably had to warrant many of them.So they after too many years decided on a slight upgrade to the 9 bolt.We are both on the same page.(At least in terms of rear differentials.:sign0020:)
 
Engine/Tranny/RearEnd/Gear Ratio Combos
S10 Pickups
1995 s10 2wd 8.5 rear, (LB4,L35,M30,GU6)
1995-1997 s10 2wd 8.5 rear, (LN2,M30,GT5)
1996-1999 s10 2wd 8.5 rear, (L35,M50,GU4,G80)
2000-2002 s10 2wd 8.5 rear, (M50,GU4,G80)
2003 s10 2wd 8.5 rear, (LU3,M50,GU4,G80)

S10 Blazers
1995-1997 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
1998-1999 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
2000-2001 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
2001-2004 s10 blazer 2wd 8.5 rear, (M50,GU6,G80)
2003-2005 s10 blazer 2wd 8.5 rear, (M50,GU6)

So... for example if you are looking for a 8.5 rear end with 3.42 gears and posi, you can find it in a v6 blazer 2wd with a manual 5spd trans...

There are also 8.5 rear ends in 4x4 s10's but i did not list them... Hope this helps you find the rear end you want. GM made two housings that came in these trucks, the 7.5/ 7.625 and the 8.5, both of which are ten bolts. The 7.5 has more of a squared shape to the cover and straight axles tubes that measure 2 3/4" whereas the 8.5 uses a round cover and the axle tubes step down from 3" to 2 3/4" near the leaf pads.

2 wheel drive width from WMS to WMS is 54.5 inches
4 wheel drive width from WMS to WMS is 59-60 (depending who measures it) inches

S10 Rear end Ring Gear and Axle Sizes:
1983 to 1992 7.5" ring gear 26 spline axles
Available from 1988+ 7.625" ring gear 28 spline axles
Available from 1995 and up, 8.5" ring gear 30 spline axles, standard for 98+ ZR2's with rear discs
This is good info, one question I have wire the Posi units real ones or G-80 Gov-locks. I broke an 8.5 one of those in 40 K in my box stock 87 GMC. They even made Gov-bombs for late 70 truck 12 bolts. If HP exceeds that of a Briggs & Stratton push mover I would not use one in a 10 or 12 bolt. What I would do is take one and swap it out for an aftermarket posi before it exploded and trashed the R&P.
 
Also, before anyone starts jumping up and down about how available these 8.5 rears are:

"For the most part, only standard shift 6cyl pickups got the 8.5 rear end, and the standard shift V6 pickup is pretty rare. Very, very few automatic transmission have an 8.5 behind them. You are more likely to find an 8.5 in a blazer, but they are still tough to find."
 
Engine/Tranny/RearEnd/Gear Ratio Combos
S10 Pickups
1995 s10 2wd 8.5 rear, (LB4,L35,M30,GU6)
1995-1997 s10 2wd 8.5 rear, (LN2,M30,GT5)
1996-1999 s10 2wd 8.5 rear, (L35,M50,GU4,G80)
2000-2002 s10 2wd 8.5 rear, (M50,GU4,G80)
2003 s10 2wd 8.5 rear, (LU3,M50,GU4,G80)

S10 Blazers
1995-1997 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
1998-1999 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
2000-2001 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
2001-2004 s10 blazer 2wd 8.5 rear, (M50,GU6,G80)
2003-2005 s10 blazer 2wd 8.5 rear, (M50,GU6)


I don't know where this list comes from, but it is not accurate.
 
Engine/Tranny/RearEnd/Gear Ratio Combos
S10 Pickups
1995 s10 2wd 8.5 rear, (LB4,L35,M30,GU6)
1995-1997 s10 2wd 8.5 rear, (LN2,M30,GT5)
1996-1999 s10 2wd 8.5 rear, (L35,M50,GU4,G80)
2000-2002 s10 2wd 8.5 rear, (M50,GU4,G80)
2003 s10 2wd 8.5 rear, (LU3,M50,GU4,G80)

S10 Blazers
1995-1997 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
1998-1999 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
2000-2001 s10 blazer 2wd 8.5 rear, (L35,M50,GU6,G80)
2001-2004 s10 blazer 2wd 8.5 rear, (M50,GU6,G80)
2003-2005 s10 blazer 2wd 8.5 rear, (M50,GU6)


I don't know where this list comes from, but it is not accurate.
http://www.lsxharness.com/336816530
 
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