I used to swear by the old school method for setting valve lash on a 12-valve Cummins
For years, I'd set them cold with a feeler gauge, fire it up, and adjust again hot. It worked, but it was messy and took forever. About six months ago, a guy at a shop in Boise showed me his method: set them all cold to the tight end of the spec, then just run it. I was sure it would be noisy, but on my personal truck, the valves have been quiet and perfect for 5,000 miles now. Anyone else skip the hot adjustment and just go with a tight cold setting?