Last week I replaced my read valve cover and did the spark plugs and wires at the same time. So when I was working on the whole project I was looking down into the lower intake and noticed some carbon build up on the rocker arms i believe and all over basically. Is there a good way to clean this? my neighbor said try using a spray bottle and spray some seafoam into the upper intake. What is a good way to do a good cleaning and what should i use?

 

If the plenum is still off I use brake cleaner to blat out the crud ... Be sure to let it evaporate before putting it back together ...
If it's back together then seafoam into it will runninng