How do these manifolds, risers, elbows look? 1998 5.0Gi's

[Monterey296Twin5.0Gi]

We suspected we were due for a exhaust service since we purchased the boat at the end of 2019. Engines are open-system ocean-cooled and neither engine ran "hot", we could always place our hand on the riser and hold it there. Taking an temp gun reading showed one riser was a bit hotter, but all close. Boat is stored in the water so we knew time was not on our side, even though every mechanic seemed to question why we wanted the service or at least know what the problem was. We just explained that we wanted to prevent hydro-locking an engine due to water intrusion into an exhaust port and they then understood the point.

So they pulled them and here are the pics. They said there was evidence was water sucking in, but not sure where that was seen. They said they only install, all new parts since they have to warrant the work, so the cost is more than we expected. These are offical VP parts, do you think it is worth cleaning these up ourselves and putting them back on?
There seems to be a lot of metal left in the gasket surface walls.

 

[Bondo]

Ayuh,... Junk,...

 

[tpenfield]

Not So Good . . .

 

[Scott Danforth]

the cooling passages are clogged with rust. time to buy new ones.

 

[Monterey296Twin5.0Gi]

the cooling passages are clogged with rust. time to buy new ones.

Thank you both for the advice. I wasn't sure if they were still cleanable, but I imagine it could be worse inside where I can't see. And to be clear we need all new manifolds, risers, and elbows?

The mechanic wants to use Sierra parts, I have read that that is a good brand for the most part for most things, but let me know if there is another preferred brand for exhaust manifold parts.

 

[Scott Danforth]

The mechanic wants to use Sierra parts, I have read that that is a good brand for the most part for most things, but let me know if there is another preferred brand for exhaust manifold parts.

shoot him

get factory parts or Barr or Osco. not Sierra, Not HGE

 

[Monterey296Twin5.0Gi]

Ha, ha. Many thanks Scott!
I will tell him Barr or Osco. not Sierra, Not HGE.

 

[Scott Danforth]

Ha, ha. Many thanks Scott!
I will tell him Barr or Osco. not Sierra, Not HGE.

FYI, VP uses Barr and Osco for factory castings.

 

[Horigan]

You're lucky. My manifold and risers looked better than yours, after taking them off due to hydro-locking my engine.