After dropping off the face of the earth for 5 years, I myself returned back to running/racing my tunnels. With new boats, had some issues with adjusting the depth. Met a good man at a race this year that gave me some sound advice. Any tunnel, start the prop shaft angle even with the spoons with 1/4" above the line. Since taking this advice, never had a problem with a good starting point. This is for all tunnels and motors.
RIP Rick....