if you get the work done sooner than later, you won't need an engine. I just recently finished an engine job on a 98 Odyssey that was completely FUBAR because of customer negligence. Obviously you want to replace the cracked radiator, along with a head gasket. Though the cylinder head is relatively easy to remove, I don't recommend it if you're not mechanically inclined. But if you're up to it...a simple service manual should be enough.