The truck has 96K on it. I just picked up the intake manifold gaskets. A
Am I right in thinking that I'm going to have to pull the valve covers as well? If so I might as well do those gaskets as well.

 

You don't have to pull the valve covers to replace the lower intake gasket, but if they haven't been replaced it wouldn't be much more work to replace those as well. If you do, be aware that the compression washers in the valve cover gaskets do have a tendency to fall out so be careful when you remove them.

Doing the head gaskets is something to consider...May not be necessary but that's your call.