Hy pan3lman, are your headers connected to a full exhaust system, or are there just headers on the engine? If it has been sitting for a while could rodents have moved into the exhaust pipes and their nest be causing a restriction?
Thanks for your thoughts! The engine was sitting in my garage for 3 years with no exhaust headers on it. Once I reinstalled it in the truck about a month ago, I was sure to put plastic bags in the exhaust ports to mitigate the chances of anything getting into it while outside. I installed the headers about a week after that max, and all of that was only about 2-3 weeks ago. I don't know if there's any chance that anything could have been living inside the cylinders prior to the engine and header install, but I'm thinking that me firing it up yesterday would have changed that really quick!
