No doubt, the 3 liter is the only car that can succeed. The silver one in the drink at VIR is such, as in the unfinished one at the shop. I haven't asked about the redline, but given that that same bottom end revs to an easy 7K in the 164 DOHC, and the fact that Alfa motors in general rev good, I would think 7-7,2 might be possible. Don't know if you'll still make power up there.
I think you're probably in the ballpark closer to 220 at the wheels. (as Jeff noticed, it won at Charlotte.. over 2 miles of straightaway)
One of the most interesting points to me is that the motor in the silver car is reported to be over 5 yrs old w/o a re-build..
The tough points (I have been told) are
1) torsion bars with a high enough rate (custom job)
2) getting air to the rear inboard brakes.
I really have the hankering to build one of these, but still haven't even had the time to get my 'B' Fiat out this year, so I guess it'll wait.