Have a 383 in the runner. Mid high rise Holley intake. When reading the plug's notice that the 3-5 cylinders are running about right as well as 4-6 on the other bank. Front and back cylinders seem to be rich on both sides. Running a 650 cfm Holley carb. The car runs fine and has plenty of get up and go. LOL. Its love's fuel. Any advice would be grate. A few other people I have talked to says if its crank's and run's just drive it. But I do like a fine-tuned motor. Is this normal for the engine. Well, any info will be appreciated. Blue.