I'm doing my first 2.3-16 valve adjustment. I check the valves every 15K miles and it has been over 50,000 miles since the valves last needed any adjustment.

The exhaust valves vary from 2 @.15mm, 2@.20mm and 4@.25mm and the spec is .25mm to .35 mm. When I order replacement shims what should I aim for? .30mm? Is it okay to leave the .25mm shims in place? Afterall going from .25 to .30 is only a fraction more than .001". Or is the .25mm the bottom limit and should the shims be replaced to bring them all up to .35 mm?

The intakes are 2@.08mm, 4@.10mm and 2@.13mm. I thought I'd leave them as they are. The spec is .10mm to .20mm or should they all be brought up to .15mm or .20 mm?

I'll also check the valve clearance with the engine at operating temp to see if the valve springs have lost any tension.

A fair amount of labor is involved to remove the camshaft(s), I want to do what is right but I don't know how important these fractions of mm are.