It would be best to measure the liner stand proud, then inspect the head for obvious damage (liner indentation, pitting, etc.) and then, only if it looks OK, hardness test the head before committing to any further expense.
The only place I know that does a proper hardness test is DVA (
http://www.dvapower.com) - Dave uses a Leeb rebound tester (which is non-destructive) to measure the hardness in all the important places. He's in Milton Keynes though, so it means stripping the head and sending it away, which costs time and some money (not a lot).
On the plus side, you can then also get him to peen the fire rings and skim the head at the same time, if skimming is required.
A lot of places will simply not give you this option - they'll want to remove the head, skim no matter what, won't bother (or even understand how) to measure the liner heights and then slap the same head back on with the MLS gasket and a so-called "head saver" shim. If the liners are wrong or the head is soft, you will get HGF again, but you can have your car back on the road in 48 hours or so.
It's entirely up to you which route you take, based on your priorities. If it were me, I would take the slow route, but I don't need my car every day (or ever, actually
).
Cheers,
Robin
