Welcome to Iboats,
Is wot rpm range 4900 to 5300 as factory stated, if so, need to go for a wot spin as loaded and report max rpm achieved on flat calm water cond to check if motor runs inside its min-max wot rpm range so to know if current prop is doing its homework right or not
Be aware that a bad transom/motor height, along bad trim and propped wrong accounts for less or slow motor performance when out of the hole. If combo doesn't count with a tach, must install one prior going for the wot test..
Happy Boating