System Design
81 rabbit diesel replace head gasket and install 204 4701 ARP head studs

It's important to note that lesser quality studs are not even centerless ground the material is thread rolled in bar stock form (mostly before heat-treat, when the material is easier to machine). ARP 260-4702 Tall Head Stud Kit for Subaru EJ25 EJ251 SOHC Phase II 2 1999-up.