If your timing chain guides need changing, now is a good time since one pivot pin is under the vacuum pump flange. Actually, there is a scallop in the flange to clear that, but pulling that pin with the vac pump on requires an offset base on the puller setup (bolts and washers work for me). But maybe forget it since you might need the engine apart more to get at that lower guide (fish it thru timing opening?). I never fooled with it since those guides may not be essential and more to eliminate slapping noise from a worn chain. Indeed, the hydraulic tensioner should keep the timing chain tight.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans