I guess after reading and searching I have come to the conclusion that headers are not really worth the trouble... and I am thinking of adding AMS lightweight pulleys and JWT cams...

I have read alot but I don't know what the final verdict on the AMS pulleys is...

Are they safe? decent gains?

Also I have an 04 non revup G35 coupe so which cams would be the best to order from JWT? should I buy any additional parts? are they even worth it?

Thanks...

 

I wouldn't replace the crank pulley unless the pulley you replace it with is a dampener as well like ATI or Fluidamper. The stock crank pulley is dampened so it is a huge step back to get an aftermarket one that is not, the additional vibrations could cause premature bearing or crank failure.

As for the cams they are not worth the cost and amount of work required to install on an NA engine. JWT S1 cams would work good if you decide you NEED cams.