Tough to answer as it depends on how smart or stupid the insurance people are as not only engine mod changes but also has a non GM calibration
They could deny claim if they catch wind of that but it they do not catch it and pay for another engine it would only be stock as to GM design
Also then with stock engine that means the existing Chuck Mallett tune will be wrong for that and would require new tuning
for stock engine to run.
Really would need to know what Chuck did as to mods and tune as I own a 1999 Mallett 435 Corvette and the engine mods (stroked, CAM, race pistons, etc) to larger fuel injectors makes the PCM tune quiet different then GM stock calibration
They could deny claim if they catch wind of that but it they do not catch it and pay for another engine it would only be stock as to GM design
Also then with stock engine that means the existing Chuck Mallett tune will be wrong for that and would require new tuning
for stock engine to run.
Really would need to know what Chuck did as to mods and tune as I own a 1999 Mallett 435 Corvette and the engine mods (stroked, CAM, race pistons, etc) to larger fuel injectors makes the PCM tune quiet different then GM stock calibration