Hello, I read the last thread of the 4.6 2v but what about the 4.6 4v. As we all know the engines that were made for the regular GT, Mach1 and Cobra is all made different. From what I know and please correct me if I am wrong the GT engines; were made of cast iron and are 2v, the Mach1 engines; are made of aluminum and are 4v with a harden crankshaft (manual only), plus they are made to breath better and last but not least by far. The Cobra engines; are hardened from top to bottom, super charged and loves to make horsepower. I have 2003 Mach 1 w/ 135,000, already the main bearing has failed in the engine, and had to replace the engine. I was told that my bearing was one of those one in a million failures that is not usual if one of the bearing was going to fail in my engine. My question is how long do you think a engine will typically last before there is catastrophic failure and have to replace the whole engine for a Mach1. Like I said my failure was not the typical failure, so I am told by the mechanics who put a refurbished engine my Mach1.