im not sure if this has been covered but i cant find much from searching (or i dont know the right keyword combinations to use)

now, i know there are a bunch of differences between the 98-00 gs400 and the 01-05 gs430 but my question is strictly regarding the engine.

what exactly changed? i came across this http://www.lextreme.com/3uzblock.html and wondered if the 3uz is a weaker(material/quality, not performance) engine?

why was the 1uz on wards top ten from 98-00 but the 3uz wasnt on the list for 01-05? does it perform differently? is it worse?

tell me all you know