Does overheated = ruined block?

[Ziegelsteinfaust]

I overheated, and cooked my 350 in my Stepside.

It did start back up after it.cooled down, but it minimally blew the head gaskets + scored the cylinder walls. Although no rod knock could be heard.

Someone told me who I think is wrong. That overheated blocks are not worth rebuilding due to changes in the cast iron. As I never worried about thing like this before when building engines.

I am planing a warm 280-300~hp DD style 350 engine for my dads B-Day/Christmas gift.

Is there some truth to what he told me.or overrated. As it will be bored, and honed again.