I installed 3.58 into my diff. Just got her re-installed yesterday. That's about as low as you can go with these diffs. That ratio is getting hard to come by these days. If you can get it, get it soon because you can only get them as good used gears.Question for those in this thread. I have a single turbo IS300 with the Y38 diff and the gearing is terrible with my V160. The stock rear end from a TT Supra is 3.133, this one is 4.1 right? Can we change the gearing in this rear end? I need more top end..
Is where I got my 3.58 gears.
A manual diff on the IS300 is 3.73 which while not great is better than the 4.1 you have now. An NA IS would benefit from the 4.1 gears you have. Maybe you could find someone to swap with?
A shop wouldn't bother to clean this. If's just minor surface rust on cast iron. If I still wanted to clean it, I'd use a wire brush or rolloc disk.Or will some good ol' brake cleaner and a wire brush work out to scrub off the surface rust?