I fully understand your preference. I'm glad you know about Utawsome though. If you're looking for anything Magnum related, they are super helpful & Marty really knows what works on these engines, it's all he does. Just check them out before you buy anything, & ask him. He will know the answers to any questions you may have. From your manifold machining pix, it looks like you know your stuff. Good luck. PS If that's a factory GC with the 5.9, (has the vents on the hood?) it's pretty rare. I've only seen 2 or three in my life & I think they're one year only. Very cool Jeep.