I just got this truck a week ago. Today I pulled the air cleaner to get to the oil sender and noticed a bit of "crud" on the inside of the intake. The guy I got it from was NOT a big maintenance guy but I am. The crud I speak of looks like remnants of not changing the air filter with any regularity. Is there a "safe" product to clean the intake out with? I don't want to load it up with B12 Chemtool and blow the heads off. It is probably a minor deal but I like the guts of motors to be clean. It is a 88 6.2. Thanks. Craig

 

Probably from the egr circulating exhaust back through, with some oil. No real need to clean it out.