Hey guy's did a little research here awhile back and found out something I did not know but 1993-1994 6.5s apparently had installed from the factory a snorkel type device inside the passenger fender well that is kind of restrictive to find out whether or not you still have this in your truck first remove the air filter and look for a black push pin behind the intake side of the filter and remove push pin then loosen the passenger side battery and move towards drivers side of engine compartment,I did not have to disconnect my battery so you may or may not have too But behind the battery on the fender well there is a 7mm screw remove this screw then with vise grips and a pry bar I was able to squeeze it out a little at a time until it was all the way out now the truck has a little more of a throaty mean sound than before Hope all this helps us early model 6.5 owners

 

here are my pics

 

get that outa there!