Just picked up a 1995 Legacy Wagon with the 2.2 engine. Looks like the previous owner caught he lower radiator hose and overheated it and now the head gaskets are shot. Puffs white smokes and overheats. Question is this is my first head gasket job on a Subaru. How hard are they. Is it best to just pull the engine. Thanks. Any upgrades to do while I’ve got it out?