timing chain tension

does anybody have a part # that I could get it from the local crazy dealership..I stopped in today and ask if they had one in stock and the guys said whats that,what does it do,wheres it at in the motor..so I told him he pulled up a few pic on the comp. and said I dont see anything like your talking about my pic dont show that it's not a part in the mag. motors..I said cool and went on my way.. I plan to go buy another dealership that only deals in mopars in the next few days...This dealership sells moparts(off to the side)brandx big building same parts house and service center.......I got a part # off mancini site but no luck with it ..thanks