Corvette sat for almost two years . Backfires now . Changed gas , still backfires

Hello, what testing has been performed? If a vehicle sits for two years, you definitely want to drain the fuel and put fresh fuel in the tank, and you want to ensure all rubber vacuum hoses are intact and connected, and that all air intake hoses are as they should be. Beyond that, testing will be needed to figure out what's going on. A diagnostic tool will be needed to see what output is occurring. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops