i have a 90 jeep cherokee with 4.0 and i just put a 93 4.0 in it and i had to use the 90 intake on the 93 because it had differnt gas lines and differnt vacuum ports too. andmy moter leaks oil when i am taking off or just giving it a little gas. the 93 moter came with a pcv valve and the 90 has something else. does anyone have any ideas?

I think the '90 had a CCV valve with a small orifice instead of the PCV valve. I cant see why you could not get the proper tube and valve cover fitting sold at Auto Zone and other parts stores and connect it to a 7/16 intake manifold vacuum fitting. The CCV valve has no mechanical spring and ball, it is always under vacuum as the orifice is tiny (around the diameter of a paper clip). The only problem I can see, depending on the smog requirements in state that you live in is that They may insist on a PCV valve for your year vehicle!