I'd drill out to a close enough size (using a drill press and fixture to make sure I'd centered the hole) and then use a
spiral-fluted reamer (a tapered reamer in the right final diameter would be better, but I couldn't find a link for one) in a hand vice (
not in the drill press) to get to the final shaft size. This way you have the most control over the final result and can take the most care.
If you use drill bits for the whole process, you'll need to get the appropriate lettered bits, as 0.335" and 0.350" are not standard inch drill sizes.
E.g.,
"R" bit = 0.339 inch
"S" bit = 0.348 inch
"T" Bit = 0.358 inch
Or in metric
8.5 mm = 0.3347 inch
8.9 mm = 0.3504 inch
You can look up other sizes on line. Graingers and other similar places should have them.
Edited by Bobtrumpet, 21 November 2012 - 06:27 PM.