Well, a quick look says the 1992 LT1 made all of 300 hp out of a 5.7l. Are you saying a displacement increase of .5l (9%) to 6.2l made and extra 130 hp? That's an extra 30% more power compared to the base 09 'Vette. I'd guess that a 10% displacement increase might give 10% more power, except that it doesn't without improving the breathing of the engine. More than two thirds of that performance improvement comes from evolution of the design; better breathing, lower friction, lighter reciprocating parts, etc.
The difference between the LT1 and the LS1 power levels is the LS1 has a much better head/intake package. The difference between the ls1 and the 3V is 65ci. The differences between the LSx and mod motors are many, any direct comparison is fundamentally flawed.
Dan