Any advise and what is the life span of the H/G?
Good advice from all the posters above.
A Subaru HG repair, if completed correctly, should last the life of the engine. So there is no randomly created time and / or mileage criteria.
The 4 main factors that go together to formulate the term
'correcty'l, in order of most occurring errors, are -
* Cylinder heads (and / or, less commonly, the cylinder block) warped from the HG failure and not brought back to Subaru tolerance by machining. Virtually all heads need to be made true again to varying degrees.
* Poor block / head surface preparation and cleaning.
* Incorrect torque sequence used on cylinder head bolts.
* Incorect gasket used for repair. Only an MLS (Multi Layer Steel) gasket will effect a permanent repair. MLS gaskets are available from several manufacturers.
Assuming you have the head gasket repaired - what's the mileage on the car? Timing belts needs replacing every 105k miles or 105 months, whichever comes first. Doing HGs is a perfect time to replace timing belts and their related accessories. And, don't forget, you don't have to wait 'til the mileage or time criteria are met; you can replace timing belts anytime before they would be due. You would then simply reset the next replacement time interval.