what is the divvrence between the rd and rd2 and whast teh diffrence for the rd. could this pistons http://www.kspec.com/list.php?ac_id=85&ai_id=1417 be put in any of the three engines or only specific ones? and could these camshafts be put into any of the three engines. http://www.kspec.com/list.php?ac_id=85&ai_id=1420. i am wondering all this because i am not sure which tiburon to get for i am carless anmd am looking into one of the three tiburons.