I would love to take the time and spend the money and do a real build. However until I am dealing with anything more than simple bolt ons and off the shelf tunes, I am happy to have at least 97s to start with. I would prefer 98 for OWC and 2001 for revised OD circuit in VB
as a baby step up from what I have now. I am pretty rough on my cars, I drive them pretty hard and do things your not supposed to do, 4-2 wot down shifts, manual 4-2 down shifts, low speed accelerating in manual second, stuff like that.
My 97 Cougar simply got the separator plate drilled to various specs, updated new style accumulator pistons, and a big cooler. Before it was just lazy and had a slight sag into one gear, and a free wheel going into another.
My 97 Mark VIII got a plate drilled out by Robert, new accumulator pistons, Sonnax pressure regulator valve and pressure regulator boost valve and sleeve. It refused to engage 3rd or 4th when WOT and letting off the throttle, it would free wheel and take 10+ seconds to shift. It also had(has) a slight sag part to full throttle 1-2 shift. This is much better now but still noticeable, but I think it is mainly because I can hear the exhaust on this car.
My 2000 Grand Marquis just has 226,000 miles on it, 7 fluid changes. It is leaking from the front pump but not tearing into it for a quarter sized drop once a week. I have stopped doing full fluid changes (14 qts draining the TC) and just do a pan drop and 4-5 quarts. With the stock programming, 2.73 rear gear, it might as well be a CVT, I can't feel shifts, TC lock/unlock, nothing.