u see, my lower unit is diff from urs. mine has lowh2o pick up, urs don't. mine also has a sharper leading edge that doesn't displace water away from the prop so more water gets to the blades. i think i can go all the way up to 3/4". the thing about the hpdi n running a t1 prop is the that the t1 props r 15 1/8". it's a big prop that needs to surface to perform best. that's why having a higher than normal rooster is norm for vmax hpdi's. yammy knew that by going to a bigger diam prop, they need more blade surfacing to help turn that monster. to do that, the normal h2o intake of the older lowerunit like urs was too high so they incorporated a lowh2o pickup to allow the motor to be raised.
as currently, i have plenty of bite. never raised it past 2" yet. maybe after n when i b&b my prop first then i'll play with the it. i don't lose any bite when turning, if u do, trim down. haven't had to do that yet. i'm running my old beat up shaved down n very well dinged prop. saving my two other shiny ones for b&b.