Originally Posted by myLEXsc400
which LSD is a direct drop in for a 97 oem w58? The TT auto diff?
I have a 93 SC (which until recently had the) original W58 5-speed with the same stock open diff as yours (4.083). The TT Auto Torsen 3.769 pumpkin will drop into any 92-00 SC300/400 but you would want no less than the gearing you already have or a 4.272 ratio (same as 93-96 Supra NA W58's). The 3.769 ratio will work but will totally kill your car's power delivery unless you're immediately going with an engine swap or NA-T build.
The absolutely direct drop in diff is an ultra-rare Torsen diff pumpkin from a 93-96 Supra NA (4.272 ratio) or 97-98 Supra NA (4.083 ratio). It's the same thing as a TT Auto Torsen pumpkin just with an NA ratio. Extremely hard to come by.
What I did was buy a 94 TT Auto Torsen pumpkin and a GS300 4.27 pumpkin and had Driftmotion rebuild the TT pumpkin with the 4.27 ratio. I kept the 3.769 TT ring and pinion for future use.
It's all tedious but it's worth it in the end.