Would seafoam help clean this (pic inside)?

[rpm]

This is a picture I took while checking the valve clearances on my Ford the other day:



I am no expert, but think it a little dirty. It also started lacking power recently.
In your opinion would Seafoam help or would it clean too much and increase oil consumption beyond reasonable levels?

It's a 1989 model with 183.000 Km (roughly 114.000 miles) on the clock.

Thanks for your input!