Years ago I ran the 2 piece ear mounts, flex would break the seal and it would start to leak. I welded a strap across the top of the ears and that stopped the flex and the leak problem. Now I have AndyF front motor mounts on 2 of my cars, I just use standard water pump gaskets and never have had a leak. I do put stress on them from torque to pounding the oil pan into the pavement.