Naprec Cast Iron Valve Guides 4G63

[e38a]

I though these were worthy of notification - http://www.rhdjapan.com/naprec-cast-iron-valve-guides-4g63.html - perfect for reasonably high powered street 4g63's

These are made in japan by a company that makes real high quality stuff

 

[nitrouskris]

Is this a troll post ?

 

[BogusSVO]

How do they differ from the readily available cast iron guides that have been in use for years?