I just purchased my first BMW it's a mint 04 325 xi with a blown head gasket. Car has 310,000 kms on it. After doing research I found it cheaper to swap engine. I found one complete engine and transmission with 200,000 kms out of a 06 x3 for 800. I'm wondering if I can just swap them out no problems. Any feed back would be great. I want to get this thing running.