How loose is too loose for exhaust flapper

[squidtone]

Hi there,
My engine has developed a noisy "TAP" RAP type of sound, an obvious exhaust leak at the manifold area. I checked the usual suspects, and eventually I could feel a blast of exhaust leaking by the gasket where the exhaust and intake manifold are bolted together. I figured I had to replace the gasket. I took the works off, but found no leak, but saw to my dismay that there is jet black soot coming out of the shaft where it pierces the casting and holds the flapper. It's pretty loose. I can shift it side to side maybe 0.025". Still, I have a hard time believing it could make that kind of racket.
The wear is in the shaft seemingly. Not so much the casting (or what appears to be some kind of bushing perhaps)

I guess it's too loose and worn, but would you agree it would allow that kind of noise to escape?
Ugh. I don't think it looks to easy to replace that shaft.

[Rus Curtis]

I was hoping someone with a flat head would jump in on this.  I've read a bunch of posts about it and it seems to be a task.  Here are a few of those posts:

https://www.thecj2apage.com/FORUMS/back-of-manifold-heat-control-valve_topic47808_post484249.html?KW=heat+riser+repair#484249
https://www.thecj2apage.com/FORUMS/leaking-heat-manifold-valve_topic1779_post10886.html?KW=heat+control+valve+bushing#10886
https://www.thecj2apage.com/FORUMS/heat-control-valve_topic9980_post79779.html?KW=heat+control+valve+bushing#79779

The soot you describe was perhaps displayed in one of the posts above.  It doesn't sound like a weekend job to me. 

Here's the kit from AJP mentioned above.  I can see what looks like bushings.

https://www.armyjeepparts.com/p-322-heat-riser-rebuild-kit-exhaust-manifold-636439k.aspx

It would be nice to be able to source just the bushings if everything else works well.

[scoutpilot]

One should not assume the shaft isn't worn.

[SteveKfl]

For the price shown in the link Rus provided, IMO... it only makes sense to follow Scott's comment... and with the amount of labor involved... to replace it all.  You wouldn't want to do it twice.  You can always make available any useable parts for others that may be "missing" the flapper and/or return spring set up.  My L-Head did not have the set up at all, and has plugs in the shaft holes???  But I live in way South Florida, its original and whole life's usage area, and it hasn't been needed like with elsewhere and colder temps.