Just my 2 cents....... for the cost of the chain, I'd do it. I know its a pain in the proverbial a** but, look at it as cheap insurance. If nothing else chains stretch and will throw the cam timing a bit which may or may not be noticable.
I've replaced several and found that it takes all of 20 min. to replace it once you are there. The oil pump chain oughtta be fine but, look hard at the tensioner rail for it and replace it if its worn. (odds are its grooved)
The big trick is cuttin the old chain off and I will use nothing more than a punch and hammer to breaked the old one. Stuff a rag to keep debris out of the oil pan
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.