FWIW, the Windsor engine was only a blip in Mustang production, caused by a fire at the Romeo plant that interrupted normal supply chains in the 99-01 timeframe. By 2002 they were back to Romeos right through the end of the 2004 MY production. Because the Windsor engine is a "truck" engine some believe it to be a tougher variant. There may be some basis in truth since the Windsor engine uses full-floating wrist pins, 8-bolt flywheels and dowels on the main caps instead of jackscrews. In practice though, the two seem to be about equal in most all performance and real-world reliability terms. In the end they both end up with PI heads & manifolds and exactly same performance.