Well fellas, I got a little bit of experience under my belt today changing out the water pump and Harmonic balancer, neither have I had to do before.
Luckily (as with my last no start/spark episode) I was checking on my bosses care homes nearby to me before heading off to other work for them 30 miles away.
ran fine Friday but this morning smelt coolant at my first home stop 2 minutes from where I live, second stop same thing... third stop the odor was stronger and took a look under the front seeing a a big puddle of coolant and no letting up. Figured waterpump failed, no surprise, can't recall if it had ever been changed before since I bought new in 99. When I pulled it it was a factory pump, so maybe not...? 310 K on the old van now so guess I can't complain too much.
The harmonic balancer has been on my to do list for a while because it has slowly gotten worse looking and separating (nearly a 1/4 inch ) so figured I better attempt tackling both at the same time.
I've read enough here to know it also a good time to do the timing chain too but with this many miles maybe not worth the cost and effort on this motor, plus didn't want to push my luck, maybe on the next one.
I was surprised the the balancer came off with the puller and not much effort, installing the new one was also fairly easy too, once the bolt was in far enough I just zipped it up snug with the air tool. The new balancer is also newer style (pulley and weight are one piece unit)
Was able to finish up everything but put the belt on and fill with coolant and burp, we'll see what new guy messed up in the morning.

If it leaks then I'll know where these 3 extra bolts go... kidding! Actually hoping no leaks and be done for a while, the way my old body feels gives me great respect for you old wrenchers who've done this type of work for a living! I've been a floor layer most all my adult life but always find sore muscles I didn't know I had working on cars

 

Considering you had to pull the water pump and harmonic balancer I wouldn't have thought twice about replace a timing set with 310K miles on it. You were just one cover away from exposing the timing set.

 

Here's a couple pictures of the old harmonic balancer. It did show that it was rubbing on the back side for about a 4-5 inch section. I had tried to upload with the first post but my phone charge port or cord is acting up

Yeah I know and may regret it, but made the call and will deal with it when necessary. Needed to get the van going again for the next day and based on how it went it worked out just right time wise for me.
Still haven't done my plenum after 4 or so years but still have the Hughes kit in the garage waiting on ambitious me to install, I keep thinking when this motor finally quits I'll do all this stuff on the next motor...
Good news is there were no leaks and my past (marginal (lukewarm type heat) is now good warm heat blowing through the vents now as opposed to before