69 N.O.X. RATT

I have friend that wants to put one in his 67.

What gear ratios are availible, particuarly 1st and 5th.
Are they a direct bolt in for an original 4 speed car
Cost / best place to get them.
Input shaft spline count

Is there two versions of this tranny, one rated for more power than the other

Any real world experiance, shifting, durability, etc.

WA 2 FST

Gear ratios are as follows (there is only one set of ratios you can get):

1st: 3.27
2nd: 1.98
3rd: 1.34
4th: 1.00
5th: 0.68

There are two versions...the standard 3550 and the TKO. The 3550 is rated at 375ft/lbs, I believe and the TKO is 425ft/lbs. I ran a TKO behind my '90 Mustang's powerplant (615rwhp/594rwtq) and it never wimpered. It is an internal rail shifted trans, so it _should_ be very easy shifting, but it is notchier than a T56 or T5 trans. It's not horrible, and with the right shifter (DO NOT use the one that comes with it), you will get good positive shifts.

It will take a lot of abuse, though.

The 3550 has a 10-spline input/26-spline output. The TKO has a 26-spline input and 31-spline output.

Hope this helps. :)

SteveG75

I got my Tremec 3550 from Fortes Part Connection in MA (I was in RI at the time). Mike Forte advertises the 3550 at 425ft/lbs and the TKO at 525 ft/lbs.

There is also a TKO II with a .82 overdrive vice the stock .68.

For the Tremecs modified for GM use, both the 3550 and TKo have a 26 spline input. I want to say that the output on the 3550 was 28 spline vice 31 for the TKO.

To install in the Vette, the following is required:
1)New tranny mount (the mounting pad on the Tremec is the same distance as that on the 700R4 .
2)Shortened driveshaft
3)Take-apart yoke so you can get the driveshaft in and out.
4)Enlarge hole in floor for center mounted shifter. Either modify the console or have the shifter modified to come through the stock location.
5)The Tremec is longer that the stock 4 spd. Option A is to make the crossmember removable. Option B is to install the engine and tranny as a unit and use a quality clutch so it lasts. I went with B.

Actually a pretty easy job. I did it myself in a 1-car garage last year. Farmed out the driveshaft and shifter mods.

With a 3:36 rear, the 3.27 first makes traction interesting, the .68 fifth lets me cruise at 70mph at 2000 rpm.

BTW: Shift effort, probably not as good as a T-56 but actually easier (if a shade notchier) than the Hurst shifter on my T-10.

Just more info from the gallery.

Distributors of GM Tremecs:
http://www.fortesparts.com
http://www.hanlonmotorsports.com

Fortes' web site has diagrams so you can get the dimensions. As for durability, over 5000 miles so far with no problems. I have the 3550 and my engine has about 370 hp and 400 ftlbs. :smash:




[Modified by SteveG75, 9:28 PM 12/15/2002]

75 BBC Stingray

Isn't there a T5, T56, T3550, and TKO all offered by Tremec and used by different forum members?

WA 2 FST

All these are now built by Tremec who bought out Borg-Warner. BW was the original producer of the T5 and T56.

You don't want to waste your time with a T5 or T45 (which are standard in late model Mustangs) b/c they are rated at ~300-325ft/lbs. Not bad shifting overdrive trannies, as I've had cars with both, but they will not handle the power from most cars on this board.

SmokedTires

I had to cut out the floor under the tunnel to be able to install the trans into my car as opposed to the hole from the Muncie. I covered the hole with a piece of sheet metal screwed to the floor.

I also had to clearance the floorpan some because of the engine offset to the right.

The TKO shifts sooo much easier than the wornout 4spd I had :) .

GrandSportC3

Of all the mods to my 68 - the TKO was by far the best one..

:cheers:

Olivier