You want 6psi in the tubes and 12psi in the hijackers.
From your photos your engine height looks high enough, maybe even too high. You could try dropping the engine so the centre of the propshaft is in line with the rope. Then if you're not getting max RPM raise the engine up 10mm at a time until you find the sweet spot.
How's your trim? got any photos or videos of it going flat out? You need to get air under the hull to make it lift out of the water.
Looks like a nice prop by the way!