You cant just swap the intake. You need the LS1 fuel rails, injectors, injector connectors, as the injectors are longer and have a different style plug in. The water pump is in the way too. Also, you would need to do the LS1 style brackets.
I think there are some ways around some of the issues, but it isnt as easy as just changing manifolds. It does look better, but there are many other things that will have more benefit.