Eaton Posi with 3.73 or stay with open???

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08-04-2005, 05:19 PM
TNT

Eaton Posi with 3.73 or stay with open???

I have a 2000 z28 with the 2 series carrier and 2.73 gears. I am going to change to the 3.73 gears but I'm not sure if I should stay with the stock open carrier and add the strange 3.73 wide ring gear or go with a new Eaton posi carrier and new GM 3.73 gears. My local shop gave me a price of $1,110 for everything installed. I think that is pretty steep but is the Eaton worth the extra $400????

That price doesn't include computer changes. What programmer or computer program is the best to use for making the changes I will need to make?
08-05-2005, 01:46 AM
SS#1531

Your Z28 came with a Torsen limited slip diff, that should be plenty good enough unless you're putting down serious power and sticky tires. In which case you would need a 12 bolt anyway. I wouldn't spend the money on the Eaton if I were you.
08-05-2005, 06:41 AM
TNT

Thanks for the input. I seem to only get the right side spinning at times and that left me with the impression it was an open rather than limited slip? Did the Z28 only come with the limited slip with the series 2 carrier?
08-07-2005, 04:59 AM
blackdog

I have a used Eaton posi unit in great shape for sale.
08-07-2005, 08:07 PM
TNT

How much for the Eaton? I'm dropping the car off on Monday evening and having the 3.73 gears put in and the thunder racing cover put on. $650 for the works plus the cost of the cover. I'm hoping that I'm not going to spend the money to spin the crap out of 1 tire. That would suck!!
08-07-2005, 08:26 PM
yak

i have a new 3 series auburn posi 240 plus shipping.
08-10-2005, 04:08 PM
TNT

SS#1531 you hit the nail on the head. Thanks for your help. I ended up sticking with the series 2 carrier and put in thick 3.73 gears and added the Thunder Racing Cover. I need to get a programmer now because my speedo is so far off. Before the gear change @ 60 in Drive 2200RPM, now 3100RPM @ 60. Big - Big - Big performance difference. (MILOC-Shorty your goin down!!!!)
08-12-2005, 04:35 PM
Shorty

Quote:

SS#1531 you hit the nail on the head. Thanks for your help. I ended up sticking with the series 2 carrier and put in thick 3.73 gears and added the Thunder Racing Cover. I need to get a programmer now because my speedo is so far off. Before the gear change @ 60 in Drive 2200RPM, now 3100RPM @ 60. Big - Big - Big performance difference. (MILOC-Shorty your goin down!!!!)

You better be spraying and praying to beat me. R/S Shorty AKA Blinx.
08-13-2005, 03:30 PM
TNT

Blinx spend wisely the next mod is the DOUBLE SHOT!!!!!!!!!! Gears won't help you. Have fun at Woodward looks like a cool place to be.
08-27-2005, 12:07 AM
BlackHawk T/A

Quote:

Originally Posted by TNT

SS#1531 you hit the nail on the head. Thanks for your help. I ended up sticking with the series 2 carrier and put in thick 3.73 gears and added the Thunder Racing Cover. I need to get a programmer now because my speedo is so far off. Before the gear change @ 60 in Drive 2200RPM, now 3100RPM @ 60. Big - Big - Big performance difference. (MILOC-Shorty your goin down!!!!)

Really? I turn 2200RPM at about 75mph...A4.
09-12-2005, 05:52 PM
TwistedSS

Quote:

Originally Posted by SS#1531

Your Z28 came with a Torsen limited slip diff, that should be plenty good enough unless you're putting down serious power and sticky tires. In which case you would need a 12 bolt anyway. I wouldn't spend the money on the Eaton if I were you.

Did the 99's come with the same differential
09-13-2005, 08:13 AM
TNT

I think the 99 is the same. When I bought mine, if I remember correctly they were the same part number for the 98 to 02 cars. You just need to know what carrier you have. 273 gears had the series 2 carrier and the 323 and 342 gears have the series 3 carrier.

http://www.thunderracing.com/catalog...&vid=3&pcid=67