Follow up. I have about 700 miles on my 'lark. It is such a great ride. The nailhead adds a good bit of weight up front from the 300, but with the UMI, and Pro Forged 7/8 instead of the 11/16. It would support a freight train. Given the change in weight and moment, the car drives as if it were designed to be configured this way. It corners flat and no float, roll, sway or whatnot. Curves I used to take at 45 MPH with the feeling that I was pushing it, I can now take at about 65 and the car still feels as if it could take it a bit faster. (but it is spirited enough that pushing it really gains little). The car launches very well, straight and no real wild up and down gyrations. Stopping aggressively is straight, smooth and much like any newer vehicle. Highway driving is very smooth and solid. I also have a close ratio box that I got from Hector (CARHEX), and it is a big part of the drivability. Can't say enough about Hector, his fast response and great communication. Hope all this helps others, and if anyone has any specific questions or need pics, let me know. I'll be glad to provide them.