First off, I would certainly hope that your brand new (rebuilt) carb would come with the necessary gaskets in the package.
If not, then check out the carburetor rebuild thread in the DIY section. I believe the kit has the gaskets in it. Better yet, you can trace your old gasket onto some gasket material and cut out your own a whole lot cheaper.
There will be a gasket between the carb and the spacer and another between the spacer and the intake manifold.
