Dan, go to Sear’s and pick up one of those telescoping mirrors that you can angle. Shine a light back there, and you should be set. It shouldn’t be that hard on this car as half the engine isn’t hidden under the cowl like certain “other” cars.
GTOWILL, this has already been discussed to some extent. The LS6 heads and cam while improved over the LS1 counterparts are not up to par with what’s available on the aftermarket. I would consider the LS6 heads and cam a “low to mid-level” heads and cam setup compared to GTP, AFR, Patriot and a few others for heads and Comp Cams, Crane and a few other cams available. I would predict that if you elected to go the LS6 heads and cam route that your rear wheel hp would be in the 360-370 range maybe 380 if lucky and/or you have a particularly strong motor from the factory.
Conversely, with some of these aftermarker heads and cam setup for about the same price or CHEAPER, you can cross the 400 rear wheel HP mark, still be fully emissions compliant, and not suffer much in daily driveability.
That’s my $.02. I have nothing against the LS6 h/c setup, just that for the money spent, you can get better results elsewhere. If you’re a purist and want truly GM parts, then the LS6 setup may be your ticket.