Yes I did according to the manual. One other thing I should have mentioned that doesn't make sense-- I noticed after inspecting the gaskets that it appears that most of the force/contact was applied to the upper edge of the gasket and less to the lower edge. This would seem to suggest that possibly the surface angles on the heads and the manifold surface angles could be off. The heads are new reman. and the manifold is original. I used the manifold on a used JDM motor and it sealed just fine. I'll re-inspect and make sure the manifold is actually seating properly