I'll be taking off my intake manifold and rear cylinder head soon enough to replace exhaust studs and the rear VTC assembly. So far the parts I have stockpiled are the exhaust studs/nuts/washers, intake manifold gaskets, head, exhaust and valve cover gaskets. I was wondering if I should replace the fuel injector grommets/o-rings and timing chain tensioners/guides while I am in there (obviously I can only get the ones on the head since I wont be disassembling the entire front of the engine).

Also, what do OEM knock sensors run about? Might replace that too since it's buried down there anyway.