Could this be from leaky valve seals? I had a very bad intake leak which I tracked down and when I took the manifold off this is what I found. By the manifold seals it is oily wet but this stuff in the port is stickier and looks old ish. Could this goo be from my bad intake leaks or other issues?

 

Looks like maybe some dirty/dusty air kept leaking in combined with blow by oil at the intake formed a funky pasty sticky mess.

 

Looks like the reason you had an intake leak is one of those intake bolt holes is stripped, or stripping, out. Probably the deposits you are seeing are caused by the lean condition from leaking seals along with oil breather blow by in the intake. I would guess you will need to remove that head to make an effective heli-coil repair, it would give you a chance to examine the cylinders and see what wear you are getting. Usually excessive blow by causes too much oil in the intake.

The valve does not show heavy deposits on it, which usually happens with valve stem seals leak, but a better indicator will be when you look at the exhaust valves. If there is built up deposit on the stem, then seals are leaking. However, if you do end up pulling the head(s), that would be a good time to go through them and maybe even pull the cylinders, re-ring the pistons and glaze bust the cylinders, followed by a thorough hot water/dishsoap cleaning of the cylinders prior to re-assembly. Provided you want/need to go that far.

 

The bolt hole in the middle picture looks stripped. How was it coming out? Have you had your manifold off before?

Jim

 

It looks as if you had an actual intake seal leak and possible a rocker cover leaking, getting sucked in, in the last picture at the top.. If it was valve seals you would see a trail leading down the stem from the guide. Repair the head and secure new intake seals.