My 2007 vmax dyno'd at 126 after about $1000 in parts, I am very sorry about my misquote, you are absolutely right about the factory HP on the Venture Royale and even after removing 200 punds, i still find it rather a dog. I did this project for something to do, likely I will give the bike away before summer and start another one.
If anybody is intersted in making a rat-venture, I would also suggest removing the stock gas tank, stock air box and battery; relocate the battery and cylinder style tank under the seat, K&N's with jetting (such as I did on my 2007 vmax) and taking the time to make a nice tank cover, remove the instrument cluster, notch the shaft drive for a larger rear tire and chop the handlebars down--which would be no easy feat.
The hardest part of all was removing the wiring that was not required with many false starts--literally.
Lots of great information on this forum!