Our G's use timing chains and to my knowledge, they will hardly ever need to be replaced. If you're worried about wear and tear, find a reliable mechanic and have them inspect the vehicle. Is your car completely stock?
The difference between genius and stupidity is that genius has it's limits...
2007 IP G35C 6MT - DEBADGED - STILLEN - MOTORDYNE - BERK - UPREV - HOTCHKIS - KOYO