Stop in for a cup of coffee

Rainy Day Auto said
Its a ford 460 1991 in an F-250

anyone know of any common vacuum leak problems and where to look ??

I assume it has a carburetor. If so, it is likely the carb/spacer gasket. Seems to be a common problem.

If not, it might be the fuel pump regulator vacuum line (but I think these were on later models).