Originally Posted by Zerodrag

If you are in SoCAL (near Long Beach), there is someone selling OEM struts with Eibach springs for a good deal in the SC300/400 forums...

https://www.clublexus.com/forums/sc4...oem-sways.html

Originally Posted by kitabel

Can't say what I would do, but:
1. Fix whatever it wrong with your spring height. If that's a high-mileage (sagging) spring replace both springs.
2. Increasing the thickness of a sway bar drastically increases its roll resistance, far beyond a simple comparo of new diameter vs. old diameter.
3. Changing only one bar un-balances the roll stiffness proportion of front vs rear. A stiffer rear bar increases oversteer, which generally helps since these (and most) cars tend to be designed with mild understeer for safety. Humor: oversteer is where the passenger is scared, understeer is where the driver is scared.
4. If you change both bars (and assuming the lever ends, bushings, etc. remain constant), the usual choice is to add the same thickness to both (like 2mm) rather than do a calculation.
5. Heavier bar(s) will reduce ride quality on a bumpy road, but not a flat road with hills - one-wheel bumps will be rougher.