Do you need to remove screw in "freeze" plugs on 427 to hot tank?

[fairlaniac]

I was told in the past that if they are in and not leaking, leave them in. Will a hot tank disturb them?

thanks,

[GerryP]

Baking, blasting, and chemical.  Makes no difference.  The core plugs have no affect of the result.  Factory heads have core plugs in them and no one has ever removed those due to some concern.

I have never had a 427 block or any block with screw in plugs, so I can't even speak to how difficult they may be to remove after decades of having found a home where they are.  On knock-out plugs, I remove those because I like to give the block an intense pressure wash in the jacket before I do anything with it and it helps to remove the plugs to get into all the crevices and flush out the silt and rust.  A pro cleaning doesn't have this concern.

[blykins]

X2....you may cause a lot of damage to remove them. 

Also, I don't know of any shops that have hot tanks anymore.   The EPA has pretty much nixed all of that.   Most shops have jet wash cabinets and if the block is really rusty/cruddy, they are sent out to be baked/tumbled/blasted first.   

The industrial name for such a machine is "Steel Abrator".  It makes them look brand new.