2 Stroke 25 Nissan/Tohatsu Cooling System Improvements

[B-Stealth]

Guys I'm running a 17X38 Carl Stryon tunnel with 8" Jackplate and I'm trying to improve the cooling system. (Low water pickup not currently option)

I have the lower unit pulled and I was thinking about blocking one or two of the smaller higher ports to allow full suction to the lowest port (the screens).

Looks like I'm pulling air from the higher ports, (the small port on very front of lower unit, and the port directly above the prop)

Any of y'all ever tinker with the cooling system, or have any suggestions?