Has any work been done to the engine or drive train since new?

There are always tweaks being done, but most are offered by after market venders. Auto makers are regulated by the Federal Government to meat safety and emission standards. Yes there are different changes that can be done, but what is offered by any and most all car manufacturers is a compromise between government regulations, competition, building costs, and what the "average" consumer will buy/wants. Corvette racing division does produce a different product, but they also are regulated by the racing body they are running in. the overall concept of the C-7 Corvette is unchanged, the engine is still for the most part unchanged, in size and build. Write to Vette magazine with this question, they should have the answer. As far as I can remember, if there are any changes, it is very minimal. What was once offered as an option order is now offered as standard on some suspension parts, but the transmission, drive train and engine remain the same.