Is there a way to tell if Vette is a real LS6 has correct tack, console plate Transistor ignition ?

Well, let's look at it this way. They are VERY rare. With 425 hp, 9.1 compression, and only 188 made. Unless you have certified paperwork, verified the Vin and engine numbers, the possibility exists. You may have one. There could be one in the bay, but is it the correct one? Further inspection needs to be done. 

From Corvette Black Book:

Holley carb  R4802A or 03A

Block stamp suffix CPW or CPX

Aluminum heads.

Without having someone that is VERY familiar with the intricacies of the LS6 cars and equipment to inspect the vehicle, it's a crap shoot. ALL of the above mentioned special parts can be duplicated and forged. There are far more "real" L88 Corvettes out there than GM ever actually produced....same goes for the LS6 cars. If you are serious about determining the car's true pedigree, I would suggest having a verified inspection done. It'll cost some cash, but if the car is real, it'll be worth it. If it turns out to be not so real, it would certainly be nice to know now.