Z51JEFF

You should be glad its not a C6,its actually alot more reliable.

Graybeard ZR1

NO stock ZR1 is going to go 11.50's, but that's not what we are talking about is it? It's clear I was referring to a 500hp. car with the top end done. And 11.60's is in the ballpark. (I said "11.50's 'sh"), guess I wasn't clear.
The example you provide proves my point. With the exception of the top end work, nothing on that engine is "modified". Stock pistons, bore, and stroke. I don't consider a modded exhaust a modded engine, but that's debatable.
There are even stock block 350 c.i. old ZR1's in the low elevens. An example is Pete from the Chicago area. But that one is cammed.