I plan on getting a posi, how soon I'm not sure, probably before april, but i need a little help with suggestions. Does anyone know what posis fit into our car so maybe i could go junkyard hunting. Also, what gearing would you suggest?

 

Any 7.5 or 7.625" 10 bolt gears and posi will work. 4X4 S10s are a good place to find high gears and posi centersections.

With a 700R4 I wouldn't go over 3.73:1 for street use. The torque multiplication effect of the torque converter will really make the car a blast to drive. On a stock engine anything much above 3.73s will quickly put the engine out of its powerband, and highwat cruising RPM will go up dramatically, even with overdrive. Also, the stock trans will downshift out of overdrive at anything above about 25% throttle, so you may end up running around in 3rd gear all the time buring a lot of gas. B&M makes a valve that can change this characteristic though.

3.73:1s are also the tallest gears you will find in a stock GM 7.5" or 7.625" 10 bolt. You'll have to buy gears to get a higher ratio, but you may find 3.73s in a junkyard.

BTW, there is no difference between the 7.5" & 7.625" gearsets. GM just changed the designation to reflect a more accurate measure at some point during the Camaros life.

 

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Junkyard gears are fine as long as they pass a thorough visual inspection. No cracks, no missing teeth, no galling, no sharpened edges, ect.

I would say that a Torsen take off for $99 is a way better deal, since it is almost guaranteed to be good and provide years of service, and you can never say that with any certainty about a junkyard posi.

I think 3.73s are about the ideal ratio for these cars. 3.42s are decent, but 3.73s would be better.

Part Number 130-70237 from Jegs gets you the B&M kickdown kit. This will delay the overdrive kickdown until 3/4 throttle is applied.

 

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Other than the 4x4 s10, where else would I find a 3.73 posi?

 

Farfire,
If I am not mistaken you should also find 3:73's and maybe a posi in Monte Carlo SS cars. I think they also had the 7.5 rear. Look between the 84' to 88' models.

 

The B&M kit will work fine wherever you drive your car. It merely delays the 4-3 downshift until 3/4 or more throttle is applied. If you need to pass someone on the highway and you floor it to go around them then it will kick down just like normal.

What it allows is the engine to cruise at an throttle position below 3/4 and still run the trans in 4th gear. This is a big help with high rear gears, because sometimes you will need 1/2 throttle or more just to maintain 75-80MPH on the highway. The factory trans would be running in 3rd gear all the time like this, which wastes gas and makes the engine run at higher RPM.

I installed the kit in my Blazer, and it is transparent in daily operation. When I get crazy and make a top end run late at night I can get so much more out of the truck because as long as I'm below 3/4 throttle I can keep winding it out in overdrive.

 

i also have found some s 10 blazers with 2.8 4wd have 4:11 gear sets

 

If you've got money lying around, go with an Eaton Posi. They have replacable clutch pads and other parts.

But BE WARNED: If you have a stock car with 2.73 or lower you will HAVE to get new gears (Eaton's posit units are for 3.00 series gears and up.) If for some reason you want an Eaton and still want a 2.nn ratio, you will still have to get new gears made for the larger Eaton Posi.

I learned all this the hard way last spring