What top speed are you currently running as 27” on the 6200rpm limiter is 84mph at 7.5% slip? 85mph I thought was the limits of the TM gear case, so sounds about right. I’d think the 300Pro XS should run 1” pitch taller prop than the 250Pro XS as it’s not making 10% over advertised like the 250 or as much power as the 300R. What are the rpms rising to out of the hole when you go WOT?