This is awesome stuff.... not to hijack the thread, but I see a lot of damage being done to moderate mileage newer engines from lean fuel (exhaust valve damage and cracked combustion chambers in newer vortecs, hemi's and LS style) and low octane fuel. It goes without saying that hardened seats are a must in older engines, and now that zinc is not widely available in motor oil (Brad Penn still does.... at almost 7 bucks a quart) is it wise to intentionally run an engine lean? The last 235 head (second gen) I had in the shop looked like it had been pounded to death. I asked the guy about his fuel purchasing habits and he said he bought whatever was cheapest. AUUUGGHHH!!! If it wasn't bad for business I ask them if they want to pay a little more at the pump or pay me a bunch of money later for valve jobs or buy new heads. Believe it or not the rotating assmblies are lasting easily 200k without a problem. Lean engines and low octane will kill your valve train. JMHO


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