Neal, this might interest you,I just got off of the phone with hotline, and I was told that as of 2001 all Romeo engines are "power improved" engines. 2000 and back 4.6's were 220 hp and 2001 and up are 231 hp. It is possible that some early 2001's are have non PI heads, you need to check the casting. The 5.4 cams are still larger, I checked the specs in the manual..I dont know if this would help or not, putting the 5.4 cams in the 4.6, I think the 5.4 really benifits from the longer stroke giving it noticably more torque than the 4.6. So as to my problem, it looks like the best way to gain any noticeable HP and Torque is a supercharger..I dont really know what else to do besides lowering the gear ratio...there is stil a possibility of trading in for a 5.4 screw so we will see...
Dave