Problems with my engine

My 91 trooper is learching while driving and there are lound poping sounds coming from the engine. The radiator is leaking somewhere and when I pulled the sparkplugs they looked good but one looked wet. Could this be a signs of a blown head gasket. I used KN head Gasket repair but it did not seem to work.

Troppers are bad for head gaskets.
do not let it get low on water, if it overheats theres a good chance of cracking head.
Keep a eye on oil for water in it, milky looking when warm, it normaly shows up when warm not cold.
Start priceing the work of new gasket