So need a 373 posi for a 7.5. Helping a friend with a low budget build 84 cutlass. Has a 307.

gnvair

G-Body Guru
Sep 1, 2018
985
93
Southern New Jersey near Philly
Yeah, most Astro Van's are 3.23 open. The Wrecker had to open quite a few to get 3.42 gears and still open.

Yeah, most Astro Van's are 3.23 open. The Wrecker had to open quite a few to get 3.42 gears and still open.
All of the 2001 to 2005 Astro vans have either 3.42 or 3.73. No 3.23's after 2000.
The earlier ones with the 4 cylinders and 60 degree V6's almost all had 3.73's
But, Astro vans used to be a great source for 3.73's
 
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gnvair

G-Body Guru
Sep 1, 2018
985
93
Southern New Jersey near Philly
The hard thing is going to be finding a used 3 series 26 spline carrier. Nothing after 88 used 26 spline so that means any vehicle you find will have to be older than 88 to get a 26 spline carrier. The 88 and newer stuff (except G body) had 28 spline. You could do 28 spline but would need a pair of axles from a 84-87 GN or 442. I did this and it works, but you need to grind the end of the axle for clearance at the cross pin. It might be more beneficial to look for a
"kit" on Ebay with gears, carrier and bearings.
 

bikerlaw

Not-quite-so-new-guy
Dec 24, 2020
13
3
I have a complete 4.10 posi rear end out of my '81 El Camino.
$400
 
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Drkuhar

Master Mechanic
Sep 27, 2018
454
93
Girard, IL
I just ordered the quick performance gm 7.5 kit. Posi carrier, bearing kit, ,gaskets and seals, your choice of gears (i got 3.42) for around 550. I also got the optional solid pinion spacer and shims that does away with the crush sleeve
 
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Oct 14, 2008
8,392
113
Melville,Saskatchewan
All of the 2001 to 2005 Astro vans have either 3.42 or 3.73. No 3.23's after 2000.
The earlier ones with the 4 cylinders and 60 degree V6's almost all had 3.73's
But, Astro vans used to be a great source for 3.73's
These are the earlier 26 spline, so pre 89. Not up here apparently. I told him 3.73 would be fine, 6 of the 8 were supposedly 3.23, the other couple, 3.42. This is what he told me. I went looking for the same thing. Surprised so many were open but I owned a 94 Z71 with factory open diffs.
 

bracketchev1221

Royal Smart Person
Jan 18, 2018
1,260
113
I did the Monte SS 3.73 rear. Got one complete and bolted it right in. I miss those days, the rear was so new it still had the drum clips on the studs.
 
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hunter_alexander

Master Mechanic
Thread starter
Apr 29, 2008
290
43
Erie Pa
Thanks all for the reply. Looking into options and passing the word. For those that offered what they have, Ill keep you posted.
 

Steve 82 Elly

Greasemonkey
Feb 2, 2020
100
43
I just ordered the quick performance gm 7.5 kit. Posi carrier, bearing kit, ,gaskets and seals, your choice of gears (i got 3.42) for around 550. I also got the optional solid pinion spacer and shims that does away with the crush sleeve
I was looking at these kits also, have you received it yet? What's your opinion? Does everything look & fit good? Just wondering what your thoughts are about these kits.
 

mc1984ss

Master Mechanic
May 18, 2020
275
43
I have a posi carrier with 3.73 gears for sale in the classified section let me know if you have any questions
 

mc1984ss

Master Mechanic
May 18, 2020
275
43
 

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