Ring gear spacer installation

[85 Cutlass Brougham]

I have a 3.23 7.5 in rear axle out of a 83 Regal, and a 2 series posi out of a 1978 Cutlass Salon ( 2.41 gear) and would like to mate the two. I plan on using a ring gear spacer and longer bolts already in my possesion as a way to mate the two and have a few questions regarding this. First off, I don't have the races off the posi, and was planning on using the races off the open diff and was wondering if this will provide me with a definite problem. Second would be weather or not the spacer will cause excessive gear noise or reliability problems ( the car has a mild 320-350 hp Chevy 355 in it backed by a TH200-4R)? It's not a drag car, but it will get pushed hard on the street. I eventually want an 8.5 instead, but this was a budget solution ( $100-120 including brakes) to the horrid 2.41 gears the car had previously.

 

[mrapii]

While what you are doing might not be the best way it should work. Just set it up like you were installing new gears; you will have to check and correct the pinion bearing preload, ring gear backlash and gear pattern. If you can get satisfactory results it should be fine. With a ring gear spacer there can be a lot of runout so check the backlash and pattern at several places around the ring gear; you sometimes have to reposition the spacer to "zero-out" the runout that the spacer causes.

 

[87MonteSS]

You're only asking for trouble with a spacer. With the power you're running I would suggest either getting a 3 series posi (best option) or buying a thick gear set for the 2 series posi.

You don't want to see what happens to the axle housing when a spacer set explodes.

 

[85 Cutlass Brougham]

You're only asking for trouble with a spacer. With the power you're running I would suggest either getting a 3 series posi (best option) or buying a thick gear set for the 2 series posi.

You don't want to see what happens to the axle housing when a spacer set explodes.

Well...I have seen what happens to a 7.5 when the spider gear pin falls out at 45 MPH and I thought it was kinda funny( broke the housing, shattered carrier and ring gear, axle came out..etc)... then again I have 4 rearends sitting around and a Nissan truck I drive every day, so if it grenades, it may not be so bad-except for the tow ( or swapping it on the side of the road...lol). I do have a 3 series gov lock posi out of a Monte SS, but would rather just get a real posi like the cone style 2 series I have, and if I found one, it would likely come in a $65 7.5 10 bolt that I would just bolt in as is without disassembly.