Tko/3550 ??
 

Came across a Transmission the seller says is a "TKO 600/3550" that he had in a "95 saleen mustang. I dont think a 3550 is a TKO 600, or that 600's even existed in '95. I'd like to pick up a 600 to replace the toploder behind my 427FE, and I have put a 3550 behind one that's still doing ok after 2 yrs, but I think I should hold out for the 600. Am I right in my thinking that a 3550 cannot be a TKO ?
Ted

Yes you are right
 

Motorhead If you are not beating on the car, the 3550 will last for some time. The torque rating is about 375 ft for that trans. You are right about the tko600 has only been out of a couple of years. This is the one that was reengineered and not breaking 2nd gear or wouldn't shift issues. The 600 is rated for 600ft of torque at a peak load hit. Some guys are running them with 750ft. of torque and 800HP. Something have to do with luck and money. I have run and will stay with the Richmond trannies. I have the 6 spd and a G-Force 5 spd race trans, been happy with both. May change my rearend to a lower gearing from 3.31 to a 3.07. If a was to buy another trans and I might, it would be the super street richmond 5 spd with a 2.87 first gear. I like the overdrive also for cruising. My 6 spd will go in am TA that the orginial reason for buying it and having a motor that made over 500ft of torque. This trans still working great and shifts smooth. Save your money and get the TKO600. Brent Bylkins sells them at a great price along with other things you might need. Clutch if you are going from a toploader with larger spline to a 26 spline GM shaft trans or needing the shorter input shaft for the tko600. You need to look into this Brent has all the answers and parts you need. Rick L. Ps need a new bushing in the crank shaft also (pilot bushing or bearing) Output shaft may also be different. Check length of trans.

It is possible the seller does not know what he has. I just purchased a TKO600 (new) and it says "TR3550" as part of the ID tag. TKO and 3550 share the same case. A 3550 will have 10 splines on the input and a TKO will have 26.

If it was the factory installed trans in the Mustang then it is certainly not a TKO.

John

Rick and John:
Thanks for the good info. It's academic now, as the unit had been sold. I did notice that the tag on it showed 3550, but don't recall if it had TR in front of the #'s. It was not the original tranny in the car, but a replacement. I'll keep looking. I'm not needing one, it would just be a nice upgrade to get an overdrive if one came along at a good price. I'm still putting the car and engine together and now would be the time to do it, but money's tight, and then I'd be looking at different clutch, maybe a different BH, so i'll probably start out with the toploader and change it out when the economy improves and my wallet is'nt so flat!
Ted

Not to take over this thread, but I have a question. I have a trans that was given to me that has a cracked main case.

The tag says TR3550 and it has a 26 spline input shaft. According to what I read above, is this trans a TKO600? I was told it was a 3550 and I just got it so I could get a used case and try to rebuild it for practice and then maybe put it in my car if needed.

The older 3550/TKOII's are not related to the new TKO 500/600's. In 1995, the 500/600 weren't available, so most likely it's a 3550.

If you could find one of the TKO II's, they were rated for 425 lb-ft of torque. Here's the thing about torque ratings. The TKO's are rated in continuous loads of torque. So if they'll take 425 or 500 or 600 lb-ft, they'll take it all the time. That means that they're pretty stout trannies.

A Cobra is a very light car and if you run street tires, the tires will break loose before it hooks up and breaks parts. For a street car, you can get away with a little less transmission.

TCRIST,

The older TKO2 trannies were available with a 26 spline input shaft....they are in no relation to the newer boxes.

Thanks Brent, So how can you tell what you really have?

Post the tag number on the metal tag and I can tell you exactly what it is.

Brent, The tag reads just as this,

TR3550 2 ALJGC 19
2600708 0041

Thanks,

The new TKO 500/600's have a part number that start with "TCET" on the tag.

Your transmission is an older TKO, 26 spline, rated for 425 lb-ft. It is classified under the "3550" model.

When I needed to replace my clutch (AGAIN, my car eats clutches) I decided to go with a TKO600 to replace the top loader. Brent provided everything I needed to do the swap, including a more aggressive clutch this time around.

Man that thing is SWEET! I should have done this swap years ago. I never ran the original shifter, opting for the Steeda Tri-ax right away. So I don't know how the regular one works, but I gotta tell ya, I NEVER miss third with the Tri-ax, which was my concern with the regular shifter.

The trans shifts really nice in all the gears, by the way, love it!