Hi! I'm new to this site. I just bought a 1983 F150 with a new 300 I6 engine. I took it to the mechanic and got a new carberator. I am not a mechanic, so I hope I am accurately describing what he told and showed me on my engine. It seems that when the exhaust and intake manifolds are correctly mounted, they nearly touch. A thick black washer and bolt is needed at different places where these manifolds meet, or nearly meet. Each washer/bolt combination serves to hold down both manifolds at the same time, but only along a thin edge of each manifold. The mechanic's complaint was that the washers were too small (i.e., the surafce areas they contacted on the manifods was too small) to hold the manifolds sufficiently tight up against the gasket. He showed me the washers AND the depressions that they set in - these depressions (with much larger diameters than the washers themselves) seemed to have a somewhat circular shape. He indicated that these depressions were meant to seat the 2 "ears" of clamp-like parts that had a hole in the center for the same bolts that held the thick washers. Because these two "ears" press against a greater surface area of each manifolds, they were able to hold the manifolds tighter against the gasket.
He looked and looked and called and called and could find no parts place, Ford dealer, or junk yard that had these parts.
Another mechanic there told me that 1977 - 1983 Ford engines used these same parts. He thinks they discontinued them around 1983.
When the new engine was installed, the previous owner could have kept the old manifolds. I don't know, but I did see the depressions where these parts seemed to fit.
He said that I need 16 of these 2-eared clamps to secure the manifolds tighter. His other option was to find or make 16 larger washers of the same thickness as those already there.
Can someone send me a photo of the part I am looking for (I can't find one on-line), or contacts of someone who has them for sale. I'll go to a junk yard and pull them myself if necessary.