It's funny but can't be done. There aren't enough multipliers and FSB speeds to hit anywhere higher than 200MHz plus those boards didn't have a way to get an odd speed like 247MHz. You had 1x-4x multiplier and 25/33/40/50MHz FSB.
BTW, in the interest of science I once overclocked a 486SX-25... forgot how high we went, perhaps to 40MHz or so. It was working... then system locked. CPU had died. My "partner in crime" was someone who enjoys a lifetime ban from here - the one and only Nowhereman!!!