Quote Originally Posted by Thomistopheles View Post
From what I've read, EJ251 is .65mm and 255/257 is .56mm.
I've read the same. Subaru has changed head gasket thickness on the Phase 2 EJ25's quite a bit. I have anywhere from 0.6mm to 1mm as the EJ251/3 head gasket. The thickness availability between the EJ20's, for example, is ridiculous. The revisions will make one's head spin.