Odds are a salvage yard selling parts on eBay wont even know the difference between a regular and Sport LS430 sway bar. If they claim to know the VIN the sway bar came from you can do a little due diligence. I would also have them send a pic with either dial calipers or an open end 14mm wrench showing the diameter is correct. You could very easily end up with what's on your car already...

 

Great point, thanks!

 

A few months ago, I spent a some time emailing every used sway bar sellers on eBay looking for the sport version. I asked if the donor car is a sport version, or if they can confirm the diameter. All of them said their sway bars are the regular version. I think the only way to get sport/larger sway bar is either buy it new from dealer, or like @rkw77080 said, get Ultra Racing bar.

I did read somewhere that the earlier 01-03 car seems to have a larger diameter bar because the bushings are larger but I am not sure if that is confirmed 100%. Anyone with 01-03 LS want to volunteer and measure the sway bar diameter? You do not need a caliper, pretty sure we just need to know the circumference of the sway bar to determine the diameter.