Opinions on this rear iron, please

[Ender]

Hi, I'm a rebuild virgin.

I'd like to know which rear iron you think is better, I think both are useable.
The engine is an S4 non-turbo. It's going to remain standard, going into my first gen.

First the one that came with my block, it's fine all over, except there's some corrosion on the coolant pipes, but what got me concerned is the amount of wear on the water jacket at the bottom:

I've seen these completely breaking, so I sprung for another used iron.

This one's water jacket looks much better and has much less corrosion on the pipes, however,

There was some surface rust on the shiny parts. Most of it was removed with carb cleaner and a cotton cloth. I used a little steel wool too, but that didn't really help. There's still some speckles visible, but it's smooth as glass to the touch.
Here's before and after:


Another thing on this one, on the exhaust side carbon has crossed over the coolant seal. Seal failure? I haven't posted a pic because there's still much cleaning to do, but there doesn't appear to be any breaks in the metal. So I'm guessing the rubber itself had a small cavity in it.

so which is worse, thin water jacket, or speckles on the sliding surface?

[j_tso]

Hi, I'm a rebuild virgin.

I'd like to know which rear iron you think is better, I think both are useable.
The engine is an S4 non-turbo. It's going to remain standard, going into my first gen.

First the one that came with my block, it's fine all over, except there's some corrosion on the coolant pipes, but what got me concerned is the amount of wear on the water jacket at the bottom:

I've seen these completely breaking, so I sprung for another used iron.

This one's water jacket looks much better and has much less corrosion on the pipes, however,

There was some surface rust on the shiny parts. Most of it was removed with carb cleaner and a cotton cloth. I used a little steel wool too, but that didn't really help. There's still some speckles visible, but it's smooth as glass to the touch.
Here's before and after:


Another thing on this one, on the exhaust side carbon has crossed over the coolant seal. Seal failure? I haven't posted a pic because there's still much cleaning to do, but there doesn't appear to be any breaks in the metal. So I'm guessing the rubber itself had a small cavity in it.

so which is worse, thin water jacket, or speckles on the sliding surface?