Gots myself a 1991 chieftain

[Cmaier8446]

so im 36 about to have my first boy ended up have a deal my may I couldn't turn down and got a 33 ft 1991 chieftain. 86xxx Mike's on him ( I say him because his name amis rocket) that's what the guy I got him from told me well long story short timing chain went bad on me after a good climb up a pass on wa .. so I was wondering if a that common for a 454ci big block to stretch a timing chain with so few miles.. I'm a mechanic so I can do the work myself how difficult is it to change a timing chain on a winnie and is there any special gremlins I should look out for