Intake gaskets

James Clews said
Contrary to other peoples beliefs I have always used the cork gaskets on the china walls! I put the cork gaskets on without installing the intake gaskets, put the intake on and cinch it up so as to squeeze down the cork gaskets. Then I take the intake back off and install it back with the intake gaskets, putting a light coat of rtv around the water passages and the cork gaskets and I have never had a leak!

You have a pretty good gap it seems. You might want to try a cork gasket and see how it fits. No need to try and seal a 3/8" gap with RTV if you have a gasket handy. Aluminum intakes aren't drilled for guide pins so if the factory roll pins are still in place you should remove them.