Just bought a smoke machine.

I used to work in a Ford dealership and the 7.5 liter and the 7.0 in medium duty trucks had problems with breaking exhaust manifold bolts. I would have a machine shop surface grind the manifolds and use new bolts and torque them correctly. Make sure that the bolt holes all still line up before you spend money on having them trued up. And yes, no gaskets on the EFI version of the Lima motor the older carb versions used a metal shim gasket. You will probably find broken bolts and may break a few removing them. This was the biggest problem with these motors that were otherwise pretty good.