Fox T-Bird/Cougar Forums  

I have a tremec 3550 in my cougar behind my 408w,  with a mcleod steal bell housing.  If I was buying now it would probably be tremec TKO 600 which is the replacement for the tremec 3550,  good up to 600 lb/ft..

here's a link with some specs:http://www.americanmuscle.com/frpp-tremec-tko-600.html

What did you have to do for a crossmember for the TKO 600?

Tremec has manufactured and is currently manufacturing the following:

T-5 (used to be owned by Borg Warner but Tremec bought them a few years back)
3550 - no longer manufactured, input shaft is an 10 spline and output shaft is a 28 spline so it works with the clutch that the T-5 was behind thus pretty popular replacement for the T-5 back in the day
TKO - no longer manufactured, input shaft is a 26 spline and the output shaft is a 31 spline which required a new clutch and yolk for the trans (usually required the DS to be shortened as well)
TKO 500 - replacement for the 3350,  input shaft is an 10 spline and output shaft is a 31 spline so you are back to changing the yolk on the DS
TKO 600 - basically the replacement for the original TKO but shifts much nicer, input shaft is an 26 spline and output shaft is a 31 spline so its a different clutch and yolk

Darren

I was just wondering why a discussion on a 5 Speeder. The T56 is as strong as a TKO600 and has an additional gear to boot. Basically you can run real stout final drive gears with a T56. In my view the TKO in 2.87 first gear ratio configuration is a good tranny but it lacks the needed sixth gear to be a real good choice. Like i said T56 is what i would do and i would not look back for one second!!