355 hydraulic tightener replacement?

I don't think Pete is planning on changing the oil pump drive chain tensioner. Although, if he wanted to do that, now would be the time.

 

Replace the four hoses at the radiators. It's easy now.

 

Drive bearing is rare. I typically only change tensioners when there is a history of rattle at startup. Thats far less rare. The good news is if they do totally fail it just rattles and tells you to replace it.

As far as using its collapsed position as an indicator they do that quite commonly when the motor kicks back when shut down. Its like a hydraulic lifter and left an hour or so with extra tension on that side of the belt from the motor turning back at shut down they'll all do that.