So this was a 2.8H, with only DT shorties and CB, and at ~ 7.5 psi of boost, on the canned KB tune, the car was making 570+ RWHP? Jesus... I'm a little confused about the knock you mentioned - was that with the canned tune, or after you were in there a little bit?
Also, back to the exhaust for a moment: Do you think a good 3" CB and manifolds would be as good a set-up as this car's current set-up (DT shorties & 2.5" CB)? I might just go 3" from the cats' and leave the manifolds; the shorties would be nice for some eye candy, but I'll need to see a completely stock car to compare for sure.
Also - I just bought the new Super Chevy and that was a good story on the 2.8H you guys had in there.