The cheap stuff is usually broken or blowed up. The engine we used in the build was a core. The customer had overheated it and popped the head gaskets. I didn’t want to put headgaskets on it and risk it dropping a valve seat. So we put a set of eagles and fresh gaskets on it and rolled on. Our latest engine is one we bought with a broken rod. Had a hole in the block the size of a quarter. Welded it up and then put a fresh rod and piston and put it back together. If you want something that is low miles and drop in ready, prepare to drop some cash...