Usually the equipment is "fine tuned
" to operate optimally at that RPM.
Since they're giving you + or - 150 RPM's....I'd set it at the upper end. You
don't want too much, but a bit MORE
....certainly wouldn't hurt the performance.
Go with 3400-3450
. More RPM's than that....could affect
how well the carburetor operates, and WHY
too much RPM is not always a good thing. S-Man