If you think you know pressure, try working on Ford's pickup truck design team. These guys are responsible for the company's F-series, the best-selling vehicle on Earth for the past 23 years. We're talking 900,000 last year alone (more cars than the European continent sent our way), delivered to the brand's most loyal and loving customers, at a much greater profit than any Taurus. That's not even counting the F-series' impact on several SUVs in the Ford, Mercury, and Lincoln lineups that net as much as 15,000 big ones per unit. It's safe to say that Ford would rather not flub the F-series at redesign time.That might explain why the magnitude of improvements in the last F-series redesign could have been measured in light years. Back in 1997 we were treated to three new engines, two of them V8s that marked the first use of overhead cam designs in a big pickup. The obsolete "Twin I-Beam" front suspension got dropped like Betamax for a coil-sprung independent setup. The new interior was as friendly as the exterior was radical. Door count went up a whopping 50%, all the way to three. Then came a fourth. Then a brand new body style that helped spread a whole new marketing buzzword: Crew Cab. Then a third box size. Then a Lightning edition that could smoke Ford's own dedicated muscle car, the Mustang GT. Wow.2004's redesign left less to improve upon, but there's enough difference to notice. The former F-150's sissyboy rounded corners were sharply squared off. Both V8s got more power. Rack-and-pinion steering found its way into all models. Disc brakes abound. The regular cab is now as big on the inside as extended cabs used to be back in the day, the windows in extended cabs now go down, and all models now have four doors. Amenities grew with interior space - egad! Is that a power sliding rear window?