grim..
i have pipes from FMF for the KX500AF conversion,(KXF450 based ),
but they would likekly work well in a kx250 to 500 conversion as well..?
but to be honest FMF simply took the low boy CR500 stamps, redid them slightly,
and yes they are dented to clear that water fitting,,
and not quite enough, =/
so i make a water fitting to change the hose angle slightly.. so all then clears well.
(on the production KX500AFs i am going to both use that water fitting, and mill the cylinder where the fitting bolts to, as there is plenty of material there to take down and help with clearence in a critical area..
with that said-
let me know if yioy want to give this pipe a try.