subie newbie

What is the wost thing that could happen if I use my EA82T heads with the typical crack between the valve seats? 3 out of 4 cylinders have the crack. 2 are tiny and 1 is decent sized and extends 3/4" into the port.

Hi. This is my first post here at USMB. I've got an 86 GL(-10?) wagon with a 1.8L turbo engine. My question is this: What part of the VIN number is the engine code? My VIN number is JF2AN55B3GD410XXX. I'm trying to order engine parts (head gasket set) and having trouble with the parts store finding the right part. Also, any suggestions on the brand of gasket? Do I need a OEM head gasket?