ZOERA-SC7XX A larger
oil pan and pickup is not going to effect you problem any more or less unless you added a HV
oil pump. You are going to need to pull the intake either way. The 2 major areas to check are where the gasket are sticking out and possibility of partly blocking the returns. Get the Flepro intake gaskets for your car and a can of HI-TAC. Spray both sides and let dry almost. Make sure that the return ports in the intake and heads is not partially blocked. Get another person to help you center the manifold on the motor. Torque down from the center out in 10 pound settings until you reach your spec. Put the distributor in it's hole before you start to bolt down the manifold. It will center it on the motor better. The other thing is which valve stem seals are you running? Can yo get a picture of them? They should have a small spring on the top part. This is a positive seal. If it is black without the ring, you will need the deflectors in the heads.
When your intake is off measure the angle of the head surface and the intake surface. It is possible that the heads where shaved. This will cause an
oil problem too. The angles could be off. Looks fine on top and is 2-4 degrees off at the bottom. You would then need to have the manifold machine to that angle.