Welcome Aboard the Good Ship Z06

Sorry to hear of your engine problem.
Of the thousands and thousands of LS7's the General has hand built, there have been very very few problems. However to hear some tell it the sky is falling.
As far as matching numbers are concerned, unless you are going to keep the car for 40 or more years the fact that is has a replacement engine will have no effect on the resale value.
I would rather have a brand new complete replacement engine than have the dealer try and repair the engine. What would you rather buy, a Z06 with brand new complete engine or one that has been rebuilt?
I'm sure others will weigh in with there thoughts.