I've seen both types used,and they appeared to be the original filler caps..best to check with a parts catalog or dealers listing to ensure the right one for the year if the engine is on it.......................................................I have a sealed one on both my 6.2's and they seem OK,but that dont mean they are the "right" ones either..I cant tell just what year engine was put in my '82 K2500,it came from a salvage yard and has no ID on it,not that I'd even know where to look for it...
