in that article car and driver and along with pretty much everyone else on this forum expect it to be 6.2L supercharged engine--so apparently--you did get your info out of your ass.
Or--apparently--you're incapable of reading.
"Lutz won’t divulge engine details except to say the displacement of the new powertrain is greater than that of the pushrod 7.0-liter V-8 in the Z06."
It doesn't get much clearer than that.
"Which brings us back to our long-held contention that the car is packing a 650-hp V-8, although we
expected it to be a supercharged 6.2-liter with an integrated intake-manifold intercooler."
Expected. Generally the past tense indicates an action or state of being in the past. In the context of this sentence, it means that they no longer expect a SC 6.2 L, but rather they know (present tense) it will be larger than a 7.0L due to the preceding quote I conveniently provided.
Furthermore, the word contention means a point which is held in debate or argument, indicating that they weren't sure! Now they are!
I love when people try and refute what's right in front of their eyes.