Might want to try BAM marine. The 3 and 5's are pretty bullet proof untill they decide to unscrew themselves.
Did that no good, there is three different sets of gears 650 hp / 900 hp / 1200 hp straight cut gear sets/ the 650 hp didn't make it. have to upgrade. 3 A and #5 are all straight cut gears and bigger shafts. I have the #3 with big prop shafts but not the better upper gears.