The Cougar did not come with a 3L???
A 3L TB is the same size as a stock SVT/ST200 TB (60mm)
However it is machined completely different and the linkage is backwards. (among a few other things!)
Modifying it to fit would be a serious amount of work and may require a bit a parts fabrication.
BTW - if you have a ST200 you already have a 60mm TB!!!
