Is it ok when the car runs rich under full boost?
Rich yes, but not to rich 12.3:1 or so is what you want to be at
Edit.....here is what I replied with on the W-body Message Board.
Factory boosted cars will probably run hella rich under WOT to prevent any possible detonation problems.... With a wide-band you would be able to see how rich is really is, max power is made right around 12:3.1 A/F ratio, and the TGP injectors from what I understand could go as low as 9:1 or so...I wouldn't be suprised if it runs as low as 11.5:1 or even lower to be safe. I'm sure someone with a Wideband and Datalogging on here would be able to verify what it really is.