Hey all...I have a series 3 eaton posi and 3.73 gears. I love them and would like to keep them.....now I have a 350 stock and a 700r4 from an 89 camaro with eaton posi 3.73...it cooks on the highway at like 4.000rpm at like 80 mph. Is there anything I can do to help this??
I have 26 or 28 inch tall tires on rear

Anyone know if they make custom overdrive gears?? To like maybe .50 or something?

It also says the carrier 3 series fits 3.23 gears and higher. Does that mean I couldn't revert to the old 2.73 gears.

I need some serious input/Advice fellas

 

2:73 2-series gear set with the 3-series carrier witll not work. Enjoy your 3:73 gears @ 4000 rpms on the highway, just turn the radio volume up.

 

Yea t56 swap an that will make ur rpm's drop big time at highway speeds

 

So dang....there's nothing I can do. So any 2 whatever gears would work for a series 2 diff. And any 3 whatever gears will work for a series 3 diff? Can I just drop down to like a 3.02 or 3.23 gears...

A t56? That's a 6-spd manual correct? If I had to go that route which I wouldn't but as a last resort could I use a 5-spd manual

 

You can go to a 3.23 gear, but no more than that. Is overdrive working in that transmission? That seem like a lot of RPMs for that combination. RPMs at 80 with a 3.73, 26 inch tire and overdrive transmission should be around 2700.
http://www.ringpinion.com/Calculators/Calc_RPM.aspx

 

Well, either what you posted is wrong or you have an incorrect tach reading.

70mph with a 26" tire is overall trans * rear ratio * 1000
So .70 (4th gear in 700-R4) * 3.73 * 1000 = 2611. That's a long way from 4000.

But maybe you have a V6 tach.
That's my best guess.

 

Hmmm well the car did come with a 2.8 mfi..
So I'm assuming the tach is still the same..

 

Well as for overdrive. Last night I had it in first and it went through all 4 gears. Shifted at about 3,000 to 3,500 rpm when it kicked into overdrive it went from 3500 to 3000 and immediately started climbing and screaming..it starts doing that high climb at about 55 - 60. .

 

Hook up an after market tach and see what your RPMs actually are. You might have a transmission problem.

 

Hmm alrighty. Ill check and hook all that up and get back to you

 

Right: if you have the 6-cyl tach and it's hooked up to a V8, then it's ALREADY reading 1.3333 times (8 ÷ 6) what it should; couple that with the tendency of these tachs to fail by reading high, and your "4000 RPM" will probably turn out to be quite a bit over-enthusiastic, like, it's REALLY about 25 - 2600 RPM.

 

Yep, that's it.

Buy a V8 tach. I don't think the Camaro ones are switchable 6 to 8 (some other OEM tachs are switchable.)