450R valve adjustment cam position??

[YZ400EX]

I am going to install an HRC cam in my 450.. I have all the specs on clearances and know how to do everything else, but my question is when getting the clearances in what position are the lobes of the cam supposed to be in or does it matter?? I just dont know if I am supposed to measure the clearance if the lobe is just touching the shim or like if the lobes were facing up (example) and measure that way..I just want to make sure I am doing this right..

Also do I need to do any adjustments on the decompression mechanism and if so whats involved with this??

[hemp450er]

you can inspect claerances with the cam in any position EXCEPT if you have a valve open, or opening. on power or compression stroke you are fine, cam should be on base circle, as for decompressor, you should have specs for that adjust it with a feeler gauge, DON'T "JUST TURN IT IN 1/2 A TURN " OR ANYTHING LIKE THAT, I think that you slide a 0.015" under decompression lever between rocker arm, and slide a 0.008" under adjusting screw, and snug up, don't remember but should be that type of precedure

[YZ400EX]

Thanks for the info.. that what I was thinking, but wanted to be 100% sure.. Now I just have to figure out the decompression adjustments for sure.. specs and all.. Thanks for the info though..