Originally Posted by TheOtherDave™

You're absolutely right as far as the USDM ITR S80 / Y80 transmissions are concerned.

We kept the same 4.400:1 final drive from 97 to 01, while the JDM iTR S80 / Y80 upgraded to 4:785:1 final drive in 1998.

To the OP: As far the LSD itself... the ITR had a helical (gear-type) limited slip which is ulmately the most durable solution. There are other types of limited slip diffs with different characteristics, but to learn the basics... go search here.