I use print-O-seal gaskets for alum intakes. seem to work fine.
first thing in the morning with the engine cold. get someone to hold a white sheet of paper behind the exhuast and start the car and rev it up a few times.
Let it dry there should be water. then look to see if there is any oil on the paper. If so its burning oil for sure. Also check for black dust on the back of the car and bumper around the exhuast. check both pipe if you have dauls so you can compare.
A good running engine will burn a lot of oil without showing many signs. Its usally the old engine that shows the oil burning with thick white smoke.
I would do a leak down and compression test before taking anything apart. no reason to pull the intake and replace the gasket if you have a broken ring land. A broken oil ring land will still run ok in a v8 but will burn oil like mad.
Hope this helps