I'm actually waiting on another lower intake right now, as the first one was welded by a shop and one side flange was warped. As soon as I get the other intake in, I can port and polish it, epoxy the EGR and IMRC holes, bolt it on and finish tuning the car. I won't be able to give a good comparison as I am going from a stock 3.8L with the vortech to the fully built 4.3L
Here's a quick pic of the motor together.
I'm not one to do writeups, but I'll add to this one if it's ok.
The 99+ Windstar requires the 99+ Windstar lower as well. The lower is actually a little longer than the mustang one and requires a little trimming up front, otherwise it will hit the timing cover. The coolant hoses, throttle cable bracket, IAC, coil bracket, and some vaccuum hoses need reworking in order to make it work.