My 98 gt mustang with the 4.6 sohc with 55k miles I noticed that I had some anti-freeze pooled below the intake manifold, I looked around it and I see that were the coolant goes across the intake manifold behind the alternator. Now i am looking for an all aluminum intake manifold, is there any avaible with out a lot of major modfications to the car. Other wise I am just going to purchase the one with the aluminum coolant plumbing.