2016 stinger pro elite 17 prop advice

[CAPTAINRUSTY]

Hello, I’m looking for some opinions on prop selection. My current set up is a 2016 stinger pro elite 17. It has a 2017 90 four stroke mercury with the 2:07 gear ratio. My current prop the dealer installed back in 2017 is a powertech eld3 in a 17 pitch. When I trim up I can hit 6100 on the analog tach while getting 43 mph on handheld gps with 16 gallons of gas, 2 people in the boat.The boat does have a little porposing issue. The motor is mounted on the second hole from the top. My cavitation plate is 1.5 inches above the bottom of the pad. I’m considering the mercury spitfirex7 prop. I’ve considered raising the motor to the 3rd hole. My question is should I go with the spitfirex7 in 17 pitch or 19 pitch. The mercury prop selector shows both props as recommended. I want to be in the upper end of my rpm range. Any suggestions would be appreciated.

[pmgoffjr]

What are you trying to get? You're doing about what I'd expect now.
Raising motor will not help porpoising, usually the opposite.

[CAPTAINRUSTY]

Thanks for the reply. I put a mercury spitfire x7 on it and picked up about 3mph and the porpoising is nearly gone.

[Mike Stephens]

Porpoising is usually caused by loss of bow lift from the prop, low speed and higher trim angles. A good prop with some trailing edge cup can generally greatly reduce or eliminate it. Raising or lowering motor is largely irrelevant, it is all about the prop. Sounds like you made a good choice for your boat. These are all custom decisions, but the basic engineering doesn't change.