Now guys remember that is an 25 year old engine,and quite possibly never been touched as far as a rebuild.I have seen far worse in far newer engines. Now that has been said Deranged is onto something,you have it out you might as well rebuild it,and possibly even do a head conversion if you want.
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If you go for the head conversion make sure you use a head from a 96-98 4.0.the newer ones are weaker and the flow is not as good.also make sure to take the full advantage and get the thingamabob in the dist hole,and the rail that goes on the spark plugs from the 4.0.as well as the wiring and computer.

BJ mentioned using castrol,personally i like valvoline,but whatever you do avoid quaker state.Also make sure to use the right grade of oil,personally i would go with 10/40 unless you plan on actually boring it over a bit,then i would ask the machinist what they recommend.

Dang i need to talk dad out of one of his 4.2's.the bug bit me good BJ <img src="/forums/images/graemlins/lol.gif" alt="" />