Just an idea.

If you are going to spend that much money and are willing to be a
guinea pig, why not try Iridium spark plugs ? You can get one for
about $8-$10 on eBay, online store like http://www.sparkplugs.com or
at some auto parts stores.

The Iridium plugs are SUPPOSED to last longer than platinum but have
even less electrical resistance than regular copper plugs (platinum
has even higher resistance than copper)

TFW

--- In clubls400atthelexuscenter@yahoogroups.com, NUHEAD wrote:
> I'm about to get my spark plugs replaced on my
> 1990 LS400 and was looking for some feedback.<br>I've
> heard that NGK is the way to go for Japanese cars but
> I've also heard that Bosch Platinum IVs are the best
> plugs on the market. They both cost $6.00 each.<br>Any
> advice?.<br>P.S.:I'll post pics soon<br><br>1990 LS400, 18" Lexani
> Solars on 235/40/18 Sumitomo HRZ II, clear bumper
> lights, 2 JL Audio 12" W3D2 Subs with 400W PPI Amp.