Most trannies from the older up till 07 can be swapped between one another. You will need the ECU pertaining to that vehicle however to operate it correctly. The best trans for holding power is the Cl-S 6spd trans because it comes with an LSD. As most know the 2000-2003 TLs had numerous problems with their auto trannies pertaining to 2nd/3rd and are very unrealiable.

You can put a 6spd tranny from a TL on a Legend?

I'm assuming so haha. I got this info from another member who told me how to do it and was planning it and was looking into doing it. So I guess it takes about the skill to do a 3.5 swap you can swap a J series tranny.