need help

how do i identify camshafts? is there a number and where would it be located that would identify what year car the cam came from...for instance i am looking for ctr/itr cams and i need to know how i can tell if they are jdm, itr or ctr, intake or exhaust, and what year the cams are? please help me...or tell me where i can find the answers...hit me back at [email protected]