just a couple of questions

my 2003 tundra will not spin the tires if i punch it off a standstill. the revs just come up to about 2500-3000 and stick there for about a second and then the revs start going up again. my truck does not have an LSD but wouldn't that just make it easier to get some wheel spin since it only has to spin one tire? and also would an aftermarket LSD be worth the money or would it be a waste? http://www.traction.eaton.com/prod3.htm
--i'm pretty sure thats the same diff as the TRD/Kazuma one (carrier only, but i'm almost positive they make one to fit in the 8")

i just recently ordered the K&N fipk. Can this void the warranty? I haven't been able to find much info about that for the FIPKs.

thanks for any help!