Ive never used them. I try and use OEM gaskets as much as i can. But i always spray my gaskets lightly both sides with gasket spray stuff. Then just to make sure theres no little leaks , do a leak down test quick if you have one or if you don't, check any gasket areas with soapy water in a spray bottle while the motor is running, spray it all over where theres gaskets or where air could get in also. If you see bubbles then its leakin.