Well I have seen some wild things. I remember seeing this crazy cv-r piston / sleeve set awhile ago on tower. I was looking for it again and knew it would have been discontinued and it is.

But here it is , pretty wild graphite piston head. I think it was $99 alone...wonder how it would have performed.

http://www2.towerhobbies.com/cgi-bin...?&I=LXGRN4&P=7

But there are some different things out there. I remember seeing or hearing about some ceramic parts too , just dont know where. Dont fully know why its not legal though.