Steven hasn't actually cancelled the kits yet. The 5/10/12 is the date he made the announcement, not the date he stopped selling them. It does say that the kits are out of stock, but not that they are "no longer for sale". I bet that his kit will bolt directly onto a 3.9 exactly the same as it does to a 3.8.
That was the best Bang For The Buck upgrade I have made !!
01 V6 5 spd
Windstar upper, shorty headers, high-flow catted X, American Thunder catback, SCT Tuner, ASP 25% UDP, FRPP T-Lok