White ashes on exhaust?

[2gdanny]

Hey guys haven't posted in a long time but I'm back with some questions, car was running great till winter came and the car is on winter mode, I wanted to get a new intake manifold so old one came out and the new one is on the way.
Also wanted to take the exhaust manifold out to get it milled as it was tru when it was last put on, when I came out I seen white spots on the ports and manifold runners, I'm not sure What it can be any ideas?
I did run 100oct from pump, 35psi
Bpr8, plugs look good and turbo is new

 

[rabenne]

hot spots? thats a lot of carbon!

 

[chrysler kid]

Hard to tell, are you running pure 100 octane or are you using a fuel additive

It looks like the car back fired pretty hard at some point as the speckles don't indicate the damage came out of the motor, but came back into it

 

[2gdanny]

I was running pump 93 and 100 mix I was driving it hard some track runs, the turbo exhaust housing. Doesn't have the white stuff on it but the manifold does

 

[rabenne]

clean up the carbon with some seafoam and check for burrs or pitting in the aluminum...

 

[2gdanny]

I was just cleaning it with a clothe and everything was coming out easy by just whipping but there's some left in the valves.

Maybe it was to much 2 stepping, would that do it ?