I didn't know if I should start a new thread on this regarding my aluminum lower intake manifold on my Buick 3800 engine. Checking flatness, what is generally the maximum allowable gaps when checking for warpage? I am measuring .005 gaps in some areas on one bank which meets up on the head. The other is much less in the .003 range in a couple areas. I am using a precision straight edge over the whole length and a feeler gauge. I would appreciate any comments/ experiences.