My 1994 GS has recently hit 43,000 kms and I decided it's time to do a valve check since it's been a while.

Results are as follows;

L/H Exhaust: 0.08mm
Shim size: 265
R/H Exhaust: 0.09mm
Shim size: 275

L/H Intake: LESS THAN 0.04mm I put in the 255 shim and it measured 0.13mm which seems to make no sense to me. Let's assume the gap with the 2.75mm shim was .03mm, dropping it 0.2mm should have put me at 0.23mm clearance. I was able to spin the bucket with the 275 shim in place. I'm missing something here. Dropping it 0.2mm should never give me 0.13mm as a gap, right?
Shim size: 275

R/H Intake: 0.10mm
Shim size:255

I'm happy with both of the exhaust tolerances and will leave them as is, but the intake specs need to change. (or is 0.10mm for the R/H intake okay?)

Any other insight from you more engine inclined folks?

Both exhaust valves look good to me as is.  I set exhaust at .08-.13 mm on my bike now. 

The RH Intake is OK at .i0 mm and I'd leave it go as is.  I leave intakes at factory .03-.08 mm factory spec since there is no need to make them wider.  I've found them to rarely if ever change thru the life of the engine.

The left intake would be OK at the measured .13  mm after shim change but doesn't need to be that wide if that is really correct.  Did you rotate the engine a couple turns or so after the shim change to squeeze out all the oil before measuring the new .13 mm gap?  If so I think it must have been tighter than the estimated .03 mm your starting with.  Shims come in .05 mm increments, my valve log:

http://img.photobucket.com/albums/v443/jcp8832/GSvalvelogs.jpg

So if I went with a 2.70mm shim on the L/H intake I'd be essentially good to go on your opinion? Even if my clearance was 0.03mm it'd put me up to 0.08mm. If my clearance was less, it'd still be within spec, 0.00mm-0.05mm.

You said the LH intake clearance was less than .04 mm with the original 275 shim and you could spin the bucket with it so changing to a 270 or a 265 should be OK.  The 270 giving you more than the .03 mm minimum and a 265 making it .closer to .10 mm like the other intake.  I'd probably go with the 265 if I had one.

Remember the engine should be turned over a few turns after the shim change to make sure any oil under the shim is squeezed out before checking clearance after the change to get a good reading.

You're a gentleman and a scholar. Thank you for the insight.