the last engine i put together would pull oil through the intake gaskets on deceleration which would puff a little blue smoke out of the tailpipes. On this engine I want to make sure I dont have that problem again. The block was decked, but I dont know how much and the intake is a completely stock weiand blower intake

I bolted one side of the intake down and measured with a feeler gauge on the other side and in the back corner I had .040 clearance and on the front corner I had .049 clearance, so the surfaces aren't exactly parallel. Also if I divide the .040 by 2 that means I only have about .020 on each side of the manifold/head surface for a gasket. Does that distance need to be a certain amount to crush the gasket a certain distance? I'm using a fel pro 1205 gasket. Basically when i do gaskets I put a little rtv around the water ports, then I spray the whole intake gaskets both sides with hylomar and i've never really had any problems...but i want to make sure everything is good on this motor since I plan on upwards of 20lbs of boost.