I just read an article in Vette mag where a peformance co. dyno'd two 06 Z's back to back to do product testing and the difference in rwhp was 411rwhp to 460rwhp between the two stock cars. WTF? Thats insane! This was done same day and dyno by same operators. I've seen some Z's dyno at 470+rwhp , but never such a dramatic difference between two identical cars on same dyno on same day. Any input as to how this can happen?