Rear gear 2.56 to 3.73

[88cscb]

hello all. Im wanting to change out my rear gears from 2.56 factory highway gears to a jegs or summit 3.73 Ring & Pinion. Would prefer just to keep the stock housing as I plan to keep the 307 4BBL, just looking for a little more gusto off the line. I already have a 200R4, so im not too concerned with high rpm or gas mileage.

Any body had this done?
And if so are you happy/was there noticeable improvement in getty-up?

I watched some videos of this being done right, and Im not attempting it myself, as I dont have a lift and dont want to get the thing 1/2 apart to find out i dont have the tools to complete the job! I assume a reputable transmission shop could do this?

 

[L92 OLDS]

hello all. Im wanting to change out my rear gears from 2.56 factory highway gears to a jegs or summit 3.73 Ring & Pinion. Would prefer just to keep the stock housing as I plan to keep the 307 4BBL, just looking for a little more gusto off the line. I already have a 200R4, so im not too concerned with high rpm or gas mileage.

Any body had this done?
And if so are you happy/was there noticeable improvement in getty-up?

I watched some videos of this being done right, and Im not attempting it myself, as I dont have a lift and dont want to get the thing 1/2 apart to find out i dont have the tools to complete the job! I assume a reputable transmission shop could do this?

The difference will be very noticeable and I think you're going to like it. If your car isn't a daily driver, I would buy the tools, do the work yourself and take your time with it. Beware of cookie cutter transmission shops like aamco. I don't like or trust them and would look for a driveline shop that specializes in rear end work. Don't forget to change the driven speedo gear in your trans.

 

[88cscb]

The difference will be very noticeable and I think you're going to like it. If your car isn't a daily driver, I would buy the tools, do the work yourself and take your time with it. Beware of cookie cutter transmission shops like aamco. I don't like or trust them and would look for a driveline shop that specializes in rear end work. Don't forget to change the driven speedo gear in your trans.[/quote]

Thanks for the advice. I do worry about a shop jacking it up. The rear end it quiet as a mouse right now, I worry about them screwing up the lash or the bearing gaps and having a rear end that whines. I also dont like to leave the car anywhere over night, it sits in my garage all the time covered Defrinately will not use Aammco or something like that. My regular guy said he would nt open one up, but would swap a whole Rear...which I dont want to do

 

[UgotBronx]

You will be very happy once it's done. And I agree get a specialty shop to do the rear. You'll have a peace of mind and a small warranty with it all. I paid a little over $600 for the whole job but it was worth it.

 

[88cscb]

Ok, I know this is an inexperienced question ( I haven't wrenched my own car since college). Where is the gear to adjust the speedo for the rear gear ratio change?

 

[crucial118]

Ok, I know this is an inexperienced question ( I haven't wrenched my own car since college). Where is the gear to adjust the speedo for the rear gear ratio change?

In the trans, where the speedo cable attaches to.

 

[DRIVEN]

Don't forget to change the driven speedo gear in your trans.

Near the bottom of this link is some info you might be able to use:
http://www.transmissioncenter.net/2004RTIP.htm

 

[88cscb]

Looked on rock auto, no dice. Will keep looking thanks.

 

[crucial118]

Check www.summitracing.com, I think that's where I got mine.

 

[2gRacing]

Interested in selling 2.56 gears? Looking for a set for my 85 Monte Carlo.