Manipulating the Numbers
Let me help a little with engine specs.....
Basic physics formula for converting between Torque and Horsepower:
(HP x 5252) = (Tq x RPM)
If you remember the graphs that show the relationship between torque and horsepower (vertical axis) versus RPM (horizontal axis), you know that peak torque occurs at about 4000 RPM. After that, there is a somewhat linear reduction in torque, as horsepower continues to rise. You can reference Jim G's charts on his truck.
I ran the numbers for the specs of a few LS2 ratings on Horsepower and the resultant torque values. I find a consistent linear relationship......
390 HP @ 5400 RPM converts to approximately 379 ft.lb. of torque @ 5400 RPM
395 HP @ 5700 RPM converts to approximately 363 ft.lb of torque @ 5700 RPM
400 HP @ 6000 RPM converts to approximately 350 ft.lb of torque @ 6000 RPM
If we took these numbers an plotted them on the "standard" LS2 engine performance graph, we should see that all the data points (both torque specs and HP specs) actually fall on the lines...... (+/- the accuracy of the data).
I think the Horsepower increase is just a marketing gimmick that the "spec" guys play with, year after year, to make us believe thay have changed something big.
Next year, they might choose to show a torque increase by specifying it at a different RPM....... Good Marketing.
Hope this helps.
Mike