I'm considering converting my car from 700R4 automatic to T56 6-speed this summer. I'm in the process of planning everything out.

Generally speaking, what would be the best rear gear to run with a T-56? I'm thinking 4.10's would provide excellent acceleration and still allow an acceptable highway cruising speed in 6th gear.

So what are gears are you T56 owners running? What would you suggest?

Thanks,

Jed
89 Formula 350

 

I think 4.10 is perfect I have 3.91 gears and I go 70 mph @ 1900 rpm. I get about 25 mpg.i am getting ready to rebuild my rearend and I going to go with 4.10 gears.

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www.geocities.com/camaro1j/myz28.html


406
accel supper ram
6000 rpm Hyd roller cam
afr heads
spohn torque arm and crossmember
t-56 trans, [wier racing bellhousing and hydrolic throwout bearing]
9" ME rearend 3.91 Gears

 

3.42's or higher are best. 3.73 seems to be a good mix, and 4.10's are nice but you'll be shifting gears a lot.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
-=ICON Motorsports=-

 

The funniest thing with the T-56 is that it is like a T-5, but with adding a lower overdrive to the mix. So if you have a gear that will keep your rpm in the power range at the speed you want to cruise at, then use it.

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'82 Firebird, dead stock, 9 bolt disc rear, over 200,000 miles and still going strong, more to come...
http://www.spinfrenzy.com/stingerssx...easures.html#4

 

N/M

[This message has been edited by johns84bird (edited May 27, 2001).]

 

I had 2.73's with mine for a while until I could afford gears. It was terrible! Basically I had no first gear. I got another rear with 3.73's and I think they are best. I still get over 25mpg on the highway and cruise at about 1750rpm for 65 mph. It might be even lower than that because my speedo isn't working correctly yet(damn cyberdyne!!) I wouldn't suggest getting 4.10's. They'll take you out of your power band too much. 3.73's might do that too. Depending on where your engine makes power I would probrably go with 3.42's if it is a mostly stock 350 that you have. You'll stay in gear longer, but as long as it matches up with where your engine makes its power it will actually be faster. My car was actually almost as quick with the 2.73's once you got rolling because I could use the whole power band of my engine. Even LS1's saw the rath of my car then .

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88 firebird formula
350 Vortec TBI
214int/224exh, .471int/.491exh
Edelbrock headers
T56 - SIX-speed
open 3.73's
2 1/4 stock catback
I love pissing those LS1's off
My Formula

All your base are belong to us.

 

I don't know a whole lot about this topic, but I know a guy who only works on f bodies. I asked him this same question once, becuase a ton of people were going with the 4.10's because they had the six speed. He told me that just becuase you have six gears doesn't mean you should use such a small gear.Most cars with 4.10's and the T-56 i have seen don't really get that big a performance gain in the quarter. that's usually what we are all looking for. The guy told me you put gears on a car if it needs gears, you can tell this by looking at where the car makes power, dyno sheets are good.that will tell you whether or not you need those gears or not.hope this makes sense and sorry so long

 

I have 3.73's now and will be going to 4.10's. With the extra OD, you have nothing to lose and everything to gain. The first gear of the t-56 loves a deep gear.

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1992 Pontiac Firebird 350/Six Speed
1987 Toyota Pickup 383/500+ HP

 

Don't forget not to overgear your car. You really don't want to be shifting into 5th right before the traps. You need to take your redline and the highest trap speed you plan on hitting into account.

Myself, I'm planning on hitting 12 flat or so with my car eventually, so I chose 3.89. With my car, 4.11 would have needed either a much higher redline or a much slower car to avoid shifting into 5th.

Of course, if you're planning on running 13.0 or so, 4.11 should be fine assuming a redline somewhere in the neighborhood of 5500-6000.

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"Beware he who would deny you access to information, for in his heart, he dreams himself your master"

'84 Black Camaro ZZ4 M5 (V-6 in a former life) -- street beast
'91 Medium Blue Metallic Z28 A4 (UB-HSTRY's old ride) -- currently broken
'99 Navy Blue Metallic Firehawk #120 M6 (99.44% stock) -- daily driver