Toyota Repair: Valve shims 1FZ-FE, valve shims, toyota landcruiser

Question
Hi, I have a 1993 Toyota Landcruiser with a 4.5litre petrol engine ( 1fz-fe ) that runs on LPG.
The motor has done 275000 km's and is down to the minimum specs on the valve shims ( 2.5mm ).
The valves clearances need re-doing so I was wondering whether you can take an extra couple of 0.1 mm off the shim ( down to 2.3 mm ) without doing any harm to the engine.
I know Toyota wouldn't recommend this but the only alternative is an expensive head reco.
The other thing I have heard of people doing is grinding a small amount off the valve stem!!!
Any help would be appreciated
Thanks Peter

Answer
The correct way to do this is to use different thickness shims that are available at the toyota dealer, this is not a DIY operation as it requires special tools, it's very time consuming. The shims are hardened steel and I would not recommend grinding them down, grinding off the valve stems seems more trouble thain it's worth and can be disasterous if too much material is removed and it is much more involved than just installing the correct shims and doing it the correct way.