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85OLDS
01-29-2001, 08:04 PM
Hi all, What I'm wondering today is, how can I get a posi unit for my stock 85 cutlass rear end without changing the entire rear axle? Can I get a posi carrier to fit from a different rear end? or do I have to find a complete posi rear end and put it in? If I have to change the rear end, what cars would have a posi rear end that will bolt right up besides the turbo regals and 442's which you don't normally find in the junk yards?
Any help or tips would be greatly appreciated, I'm sure that lots of you have put a larger engines in your cars and had to deal with upgrading the open diff's to posi units. Thanks in advance.

79CutlassSupreme
01-29-2001, 08:18 PM
I feel the best way to get posi traction is from installing a Powertrax locker. You don't have to remove the ring or pinion gears to install. The locker will unlock around turns and always lock posi when streight. The locker will make a clicking noise some times when turning, doesn't bother me though.

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http://www.dickmillerracing.com/RupStock00.jpg
'79 Cutlass Supreme 350 Olds 13.55 @ 99 MPH
'85 T-Type 231 Buick 12.58 @ 105 MPH
'86 GN 231 Buick ?????
'96 Impala SS 350 LT1 14.71 @ 93 MPH
'00 Silverado 327 LS1 16.30 @ 83 MPH
'79 LeSabre 301 Pontiac 18.11 @ 76 MPH shooting for 17s, cam & intake swap complete!

83 H/O
01-29-2001, 08:24 PM
If you are not real familiar with carriers, you may just want to find a GN or 442 rear and bolt it in. 442's have 3.73's and most GN's have 3.42's. I'm sure most people on the board can help you with the axle code stamp. E-mail me if you need them for the years around yours.

Keep in mind that the some GN's and 442's came with "one-leggers" (my 83 H/O did).

If you know how to identify carriers, a nice tip is:

A lot of the Chevy S-10's from the same era as your car, use the 7.5" housing but use the Stronger Auburn Carrier. I have worked on several in the past. Auburns in the S-10 will accept the 3.42's and 3.73 Ring and Pinions.

Some people don't care for the 7.5 (me kind of being one of them) but they "hang in there" pretty well. My 7.5 in my older 83 T-Type has the Auburn Carrier and 3.73's and has done just fine.

Hope that helps.

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I'm not driving to fast, I'm flying to low.

83 H/O Stock
83 Buick T-Type Stock
86 Buick GN - 11.94 @ 116mph
79 T/A 468 Olds W30 - 10.86 @ 127.2mph
..and let's not forget the wifeeee's "UltraFast" 99 Alero GLS 3.4 Grocery Runner.

79CutlassSupreme
01-30-2001, 05:18 AM
All GNs and T-types (84-87) came from the factory with 3.42 gears. The Powertrax locker installs easy. The instructions are good. Can be installed in your driveway in a half hour.

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http://www.dickmillerracing.com/RupStock00.jpg
'79 Cutlass Supreme 350 Olds 13.55 @ 99 MPH
'85 T-Type 231 Buick 12.58 @ 105 MPH
'86 GN 231 Buick ?????
'96 Impala SS 350 LT1 14.71 @ 93 MPH
'00 Silverado 327 LS1 16.30 @ 83 MPH
'79 LeSabre 301 Pontiac 18.11 @ 76 MPH shooting for 17s, cam & intake swap complete!

[This message has been edited by 79CutlassSupreme (edited 01-30-2001).]

85OLDS
01-30-2001, 06:18 AM
79CutlassSupreme could you give me some more information about the PowerTrax locker, like where to buy one and what model to buy? I think that's what I will do. Will it work with the stock 2.42 gears I have now? Thanks for information in advance.

83Cutlass
01-30-2001, 04:41 PM
http://www.powertrax.com/

Hey 79CutlassSumpreme,
How does that Powertrax work? I guess its suppose to replace the spider gears, right? I went to their website and see they have three choices. Which one to you have? How much did it cost?

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1983 Oldsmobile Cutlass, 3.8L V6 and THM250c (yanked July 30, 2000). Getting ready to drop in a 383 stroker and a THM350 with a homemade shift kit (I know its a Chevy motor, but oh well. Actually I got it in finally Aug. 26,2000 ). 383 Stroker specs: 4-bolt mains w/ ARP main studs, Scat crank, stock 5.7" rods w/ARP wav-locs, .030" over, 9.6:1 Comp ratio, Trick Flow heads, ARP head bolts, Summit roller rockers, Comp cams 268H (268 adv. duration, .454" lift), Hyperuetechtic pistons, Flowtech Afterburner headers, Edelbrock Performer intake, Mildon high flow water pump, and fluidamper balancer.

79CutlassSupreme
01-30-2001, 04:56 PM
I have the old one. The $300 one. The $400 one is newer, I guess stronger too. I have had no problems with either of mine. The Cutlass has one in the 7.5 rear and the T-type has one in the 8.5 rear. It will work with any gear ratio. All you have to make sure of is getting one for your diff(7.5 or 8.5) and the correct axel splines(26 usually on 7.5). You can get one from Summit or Jegs.
The locker takes the place of the spider gears. It installs very easily. Most of your time will be draining and filling the diff.

------------------
http://www.dickmillerracing.com/RupStock00.jpg
'79 Cutlass Supreme 350 Olds 13.55 @ 99 MPH
'85 T-Type 231 Buick 12.58 @ 105 MPH
'86 GN 231 Buick ?????
'96 Impala SS 350 LT1 14.71 @ 93 MPH
'00 Silverado 327 LS1 16.30 @ 83 MPH
'79 LeSabre 301 Pontiac 18.11 @ 76 MPH shooting for 17s, cam & intake swap complete!

85OLDS
01-30-2001, 05:04 PM
Thanks for the info. It says that the new one is better for the street because it supposedly doesn't make the clicking noises when going around corners. I think I will look into buying one when my wallet recovers from the 403 Olds I'm putting in this weekend. Thanks again.