"water jackets?" in the timing chain cover 1977 400

I am rebuilding my engine for my trans am for the second time, the last time I had this engine apart was 1984. I am cleaning my timing chain cover and noticed rubber  ring and metal ?water jackets? that feed to the block (I am sorry I don't know what they are called) my question is should these be removed they appear to be metal (brass colored). I don't want to trash my timing cover by taking these out if they are not supposed to be removed completely, but they appear to be corroded in to the cover.  
My 1978 T/A the only thing that I ever loved that didn't leave me stranded (Yet)

Yes the metal tubes are replaceable but if the metal tubes clean up and are still in good shape then just replace the rubber o-rings which should come in the complete gasket kit.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

Thanks Pontiac man
My next question then, do they press out? if I destroy them while getting them out where would I get replacements? I am sure I don't need to tell you how hard it was to get the timing chain cover separated from the block two of my bolts broke as they were corroded into the cover had to break them off in the block and drill them out.  
My 1978 T/A the only thing that I ever loved that didn't leave me stranded (Yet)

Yes they should press out but that is easier said then done if they are in fair shape then you may not have to remove them to clean them up but if you remove them be sure to replace them yes you can buy them from www.pontiacengines.com he sells them for around $15 or so or you might fined a set on ebay.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races

Well broke my timing cover trying to get them out I have a backup cover that does not have the inner sleeves in it so I emailed Pontiac engines for a new pair thanks for the advice Ponitiacman your advice was spot on my execution not so much  
My 1978 T/A the only thing that I ever loved that didn't leave me stranded (Yet)

Yep I always keep a spare timing cover you just never know.
Your welcome.
Anything else just ask.  
professional hi-performance engine builder

Horsepower sells engines and torque wins races