[font size="1" color="#FF0000"]LAST EDITED ON 29-Sep-00 AT 02:25 AM (EST)[/font][p]I have a 1984 F-150 with a 300 c.i. inline 6 cylinder. I purchased it 7 years ago and have always had trouble with a leaking intake/exhaust assembly. A few years ago I noticed an exhaust leak at the connection between the manifolds. I removed the assembly and realized that the butterfly mechanism (heat riser flapper) had completely disintegrated. I temporarily fixed this by sandwiching a piece of galv. sheet metal between the intake and exhaust manifold. Of course, now the heat riser no longer functions but the only consequence is that it takes a little longer for the engine to warm up in the winter.

Now I believe this temporary fix is wearing out. I have noticed the exhaust sound is getting louder and it is leaking between the manifold assembly again.

My question is does anybody know of an aftermarket parts house that sells replacement exhaust manifolds for the 300 I6? I checked at a Ford dealer two years ago and they wanted $400 for it. Could I get one from a junkyard off a later model f-150? I don't know if the later model exhaust manifold would work. Also, does anyone know how to make a long lasting seal between the intake and exhaust manifolds?

Thanks,
Mark H.