What is the old one made off? That's quite risky thing to do and I would highly recommend not to do it. If the old gasket is made of metal I assume you can get away with using Hight temp gasket maker, I did on the turbo car running 22 psi,but that was because it was my only car and I had to wait 2-3 weeks before getting new gasket, I replaced it as soon as I got it. Sent from my ONEPLUS A3000 using Tapatalk