What I dont understand is this.
Amount of time invested to remove said hardware to install said gasket without having thought about the consequences of having your cheap arse product fail, not line up etc and then going through the process all over again or having the vehicle in the shed, not on the road in quick time.
Warps, you say price doesnt dictate quality. In brand new products this is not the norm you must admit.
Like Ive said to the OP. Go to a local shop where the owner cares about their business and rep, pay the right amount of money for the right product and be happy in the knowledge that you will get face to face support + you have supported a local business.
Its pretty fkn simple.