It's only on the left side of motor manifold and carb are stained looks brownish in color back left corner of motor by spark plug wet with oil/antifreeze also under car .does it sound like gasket of crack block
I have a Chevy with a 350 looking at motor left side exhaust wet with oil/antifr on 1990 Chevrolet Camaro
Oil leak, most likely valve cover gaskets. Antifreeze leak, most likely water pump. To be sure, most likely need a mechanic to look!!
AGREE WITH PUHROD BUT ALSO COULD BE HEADGASKET
Answers 1 and 2 cover all your bases!!