97' legacy outback wagon does have hydraulic lifters.
(mine does)
Subaru has used at least three different heads and valve covers, also cam cap bolts can be 6mm 0r 8mm
torque 6mm to 7ft lbs and 8mm to 14 both torques ar specified in subaru shop manual w/o clarification as to why . Be sure to get the correct small valve cover gaske tthere are 3 different versions,