Just bought a smoke machine.

Yeah no gaskets on them. And FYI the EFI 7.5L (460) has different heads than a 86 (I think) and down 7.5L. The ports are different. You can tell the EFI heads by the center bolt down valve covers. The Exhaust ports are raised and smaller than the older stuff so you might look at the manifold castings and see if the part numbers are correct for the year. As I recall the old stuff bolt on but do not line up.