Not a lot of progress to date other than fixing everything that didn't work prior to ripping it out and selling it off to finance the purchase of more stuff to put back in.

Planned class is E/Pro, current record is 165 and change according to the website so well within reach. The stock US variants will reportedly do 150mph in factory trim and would do more but are speed limited. Aussie and Jap versions are speed limited to 180km/h and 6500rpm.
The engine is an all alloy, 32 valve, quad cam 4.0L that comes factory with 6 bolt bottom end. Stock HP was around 250 to 290 depending upon model. The early versions with their beefier rods can purportedly stand up to 800 flywheel hp before you should get scared.
The only Cd info I can find is from the US Lexus owners manual. It states .32 for the bare body and .31 with the boot spoiler. Mine also has the front lip that was never released in the US but did come out both here and in Japan. It has 21.5 feet of frontal area for the technophiles.
That's about it in a nutshell, I'll get a pic or two up later.
Cheers,
Rob