I bought a set of feeler gauges from Sears. The package states these are "offset 45 degree for checking of "V" engine valves." I am wondering if these are the correct one for a 2001 gs500? Also the blade sizes range from .13mm to .76mm. Is this the correct range for most applications? Thanks so much for your help?
The 45 degree offset isn't really of benefit on the GS, although I'm not sure if it will make it harder or not.
The range isn't too useful for the GS. The primary thing you will need feeler guages for will be to check the valve clearances. The spec is 0.03 to 0.08 mm, so you should have feelers that go down to 0.03.
If you haven't opened the package yet, I suggest that you return it. As far as the valves go, the optimum clearances are from .03 to .08 mm - way too small for that set to measure.
For your spark plug gaps, get a (probably cheaper) set of wire gauges meant for spark plugs. The correct gap for the plugs is somewhere between .8 mm and 1.0 mm - too BIG for your set to measure.
I can't think of anything else that needs to have the clearance checked. Of course, I've never split my engine cases....