Got a coolant question

Ok im no ace mechanic here guys but i do know my way around engines ok,ive run into a weird problem here lately with my 88' 3500 dually with the 350 fuel injected engine, i fill the radiator and after a couple days the level drops a few inches.

Now the weird part is this truck doesnt leak,the oil looks fine and so does the water, ive noticed around the intake the it looks a little damp, and also down on the radiator spigot on the bittom where you dran the radiator looks damp, you guys think im just dealing with a bad radiator here?

Bad intake gasket. I've sen them leaking coolant into the cylinders slightly where it didn't affect the engine when running. Get a coolant pressure tester and pump it with pressure. Remove plugs one by one and see if that is where its going.

Thanks brian, i'll get one. I always thought if it was the intake gasket you would be showing high oil pressure on your gauge?

Only if you see water on the oil dipstick. It usually leaks into the cylinders and gets burned blown out through the exhaust. The gaskets are narrower close to the exhaust ports and usually fail there first.