Derbis do better with not insane exhaust durations and blowdown. 10k is really where Flat reeds seem to like to be. that in mind I leave them in that range.
on metra 47 I do 180-185° exhaust and try to get the blowdown of around 18°, on a single exhaust port smaller displacement top end I'd probably go more conservative and less revvy at 170° and 15-16°. Other than that just widen as much as you feel comfortable and get the squish real on point around 1mm. Should be broad enough power.
as mentioned they're pretty great even unmodified and all that time might only get you 2 or 3mph but, such is life ¯\_(ツ)_/¯ (edited)