hey everyone, i recently blew my motor due to a bad tune before i purchased the car. I need to get a new block, and i was going to purchase from either AMS, Buschur, etc. when i have the funds.

My question is, they say **GOOD CORE REQUIRED** and then they have a core charge of whatever amount. Does that mean in addition to purchasing the block i have to spend the extra amount? I'm kind of confused as to what they mean by that. Can anyone help me out and give me some insight before i make my purchase? thanks