I've been searching head info too. What I do know is that the Romeo heads have the 11 bolt valve covers. The Windsor heads have 13 bolt valve covers on the driver side and 14 bolt valve covers on the passenger side. Not sure if all of them have this but there is a PI stamped right under the part numbers on the head. On my driver side head, it is stamped just above the exhaust manifold towards the back of the engine or near the #8 cylinder. I currently have Patriot Performace stage 2 heads that are actually Ford cores that get worked. Mine are PI and Windsor which seems to be the better heads from some of the searching I've been doing. Here is a picture I found on google. Look just above the #8 exhaust port, right under the Ford part number is the PI stamp.
2001 GT. Oxford white. Patriot Performance heads. Comp cams. Ford Racing shorty headers. BBK under drive pullies. Roush CAI. 3000 Stall speed converter. 4:10 Gears. Bullitt calipers. Frame connectors. Bassani exhaust.