Congrats on the Cobra. You should do a check on the build date of the Cobra. Some of the early production units had cylinder head problems. My first '03 Cobra customer did mods similar to what you're talking about. He burned a valve and broke a piston. We ordered him a new motor but Ford sent up the red flag and made us wait for an engineer to inspect. They saw evidence of a chip, and marks on the bolt to the upper pulley, took pictures, and then voided his warrantee. The motor replacement was going to be $15,000. Be careful.