Should I stay with my stock 3.23's or are they too tall for a T-56?

3.73's?
4.10's?

 

I put an aftermarket T56 in my car and it has very similar gearing to the stock T5. I just left my 3.08 gears in, since I like the rpm band it sits in. Of course I'm looking more at pro touring, so it works for me. I take it you have the factory 94-97 T56 with the taller 2.66 1st gear? In that case if your looking mostly for the street I'd try your stock 3.23 gears. If your looking for quicker ET's then try 3.42 or 3.73 gears. Don't go to low though if you have a TPI setup, or you'll put the motor above its powerband.

 

I have run 3:42's, 3:73's and 4:11's with the T-56 and could have gone even deeper. The T-56 loves gear, but I found the 3:73's were my all around favorite.

 

Just some info for you guys here,

I just recently got the latest Jeg's and looked under
transmissions to check out the aftermarket ones.

Richmond actually has 4 different sets of gear ratios for
the T-56.

So, you can choose trans. , not just rear gears.

Check it out here too....http://www.jegs.com/cgi-bin/ncommerc...43&prmenbr=361

 

if i had a T56 with dual overdrive............4.56's

mainly because i like the feel of a torquey car, and i dont really race so i dont care about traction really

 

Richmond DOES NOT make the T56

they make a 6 speed, but its an entirely different trans altogether

 

Yep, T56s are made by TTC automotive. www.ttcautomotive.com


"TTC is a joint venture between DESC's automotive operation and Dana Corporation, traded under the NYSE symbol DCN. With the acquisition of TREMEC in 1994, the acquisition of Borg Warner's manual transmission operation in 1997, and the relocation of Dana's medium- and heavy-duty transmission operation in 1998, the Transmission Division became a full service Tier 1 transmission manufacturer."

There you go, that's who makes the T56, T5, T45, and many other products.

 

Yes, your right.

It's a more bullet proof version, "GM" style trans. Guess maybe
for like an 8 second or lower car.

Cause I know that the newer version ( 94-up) T-56s
are made to handle pretty good.

So, there is no need for those trans. , I think a stock
T-56 are just fine for 300- 450hp.

 

The richmond 6 speed has only one overdrive with 5th gear being 1:1. A T56 has 4th gear as 1:1. The richmond is simply a different trans, with closer gear spacing for possibly better acceleration if you have the motor to match.

 

Just a data point for ya, I ran my T56 (swapped from a '97 TA) for a year with 3.42 gears, then swapped to 3.73. It really likes the 3.73 all around, didn't hurt my mileage significantly, and really snaps the car when the gas is mashed.

The 3.42 was OK too, but not as zippy as the 3.73 w/ the T56. Previously I had a TH700 trans and 3.42 was as high as I'd care to go for rear gears w/ that.

 

Tom84L69,

Yes, I forgot that the stock GM factory T-56 trans. does
have the "double" overdrive. The Richmond does not.

I believe this time I'm right, no?

I'm a "rookie" about the T-65, can't you tell?

another thing,

You guys talk about gear swaps in your rear.
I know your running a T-56 trans. but what HP/torque
are you pulling? Is your rear end the stock 10 bolt?

Can a stock 10 bolt rear end ( with welds to the axle
tubes, a stud girdle, and 28 spline axles ( 1991 Camaro)
hold up 400hp/ 400 ft. lbs. ?

 

The rears are a funny thing. I know of a stock rear running in the 11's and yet I blew mine with a 14 second car. I am sure that the auto trans vs. manual trans has something to do with that though.

If you build the rear, there is no doubt it will handle a bit more power, but how much more is any ones guess.

I am having a 9" cut down now, before the 383 goes in. I picked the 9" because I have 5 of them here. If I did not already have them, I would atleast put a Chevy 8.5 together for it.

 

Thanks for the info.

I would rather buy a Moser "Chevy"12 bolt rear than to buy a
Ford 9" ( only reason: F O R D ! I don't like FORDS! )
Plus Moser 12 bolts are slightly cheaper.

I know they are the best thing since sliced bread,
but I'm only talking 400 hp/torque range, not like
800 hp.

Everyone has there thing with what rear to use.

Some say a Ford 9", others say a Chevy 12 bolt will
be just as bullet proof.

Once the motor and trans. is in, I will find out then if
it blows up or not!

 

Thats why I said I piccked the 9" since I had a bunch of them laying around. If I did not have them, my choice may have been different, or maybe not.

Check your 12 bolt pricing again. I think you will find it is more expensive in the end. The internal parts cost more than a 9". Housing may be cheaper, but thats about it. The 9" is a more popular rear, since it was put in a ton of different cars and trucks and not just a few HP models like the 12 bolt. This helps keep the cost down.

Either one will work fine in our cars. Whickever one fits you budget is the way I would go.

 

Good topic. I was just thinking of posting a vote.

One thing I have been researching is final drive ratio. This is done by multiplying the trans gear by rear end. Looking at first gear in a bunch of different tranny's:

.................t56......... 700..........stang T-5....... T-5
1st...........2.68.........3.06............3.35...........2.94

Rear....................Final Ratio In First

3.23.........8.59.........9.88.........10.82.............9.50
3.42.........9.10.........10.47.......11.46............10.05
3.73.........9.92.........11.41.......12.50............10.97
4.10.........10.91.......12.55.......13.74............12.05
4.56.........12.13.......13.95.......15.28............13.41

What is interesting here is what how low of a gear you would need to meet the same final ratio of other tranny's compared to the t-56. I added the mustang in here because of the fact it has a pretty insane 1st gear compared to the others. Besides weight, this is the main reason that the M-5 stangs run so much faster than a auto. The auto I think is even numerically lower than 2.68.

Anyway, I went from the 700 to the t-56 w/ the 3.42 gear in at the time of the swap. As you can see, in order to get the same ratio of the 700, you need a just a tad under a 4.10. I liked the first gear pull with the 700, and hooked well.

All thing being equal, if you are running vs moosetang with 3.73's, even with 4.56's the final ratio would be higher (Numerically lower, remember lower gears mean higher numerical value and vice versa)

I also looked at what my predicted trap speed would be and what gear and rpm I would be in. Anyone running a stocker with 3.42's will acknowledge that you are just coming out of 3rd and could or could not shift into 4th just before the traps. With a 24.6" tire diameter, 4th gear, 3.42's and a M6 at 5000 is 107 MPH.

For a 4.10: 89.29
for a 4.56 80.24

My best trap speed on again a stock ride was 86.00 with a 16.2. (I hit that shifting first at 4500, the rest at 5000, which for some reason keep my car in the power band better)

You have to take in account what your top RPM is as well as what your predicted MPH is through the traps. Add 500 more rpm if your motor makes power to there and the 4.10's jump out to 98.21, 4.56 to 88.31.

I have a simple excel spreedsheet set up to determine all this if anyone care to have it, let me know.

Anyone shift into 5th at the track?? I would think since it is OD, that would would want to finish at redline in 4th. Just curious.

 

You can buy T56s new with a 2.95, although some have the 2.66. TTC's website has a list of ratios that is helpful, link is in one of my posts above.

you are correct though; my dad has a 62 impala ss with an M21 and a 4.88 rear gear. The M21 has a 2.20 first gear. My Z with a T5 and 3.73 has a better first gear ratio than his. cool

 

for rear end gear i would say.....
3.42's for the street
3.73's for the track.

depends on what u use it most for.