I know nothing about Viper engines. That said I have built numerous drag race engines, mostly Chevy and Ford, big block and small block.
A blue printed engine carefully put together with uniform clearances will make more power by reducing friction losses.
Carefully blue printed oil and water pumps can reduce the amount of horse power needed to run them. By carefully running as light weight valve train components as you can find and reducing the tension of valve springs as much as you can will also reduce frictional drag.
Careful polishing and shaping of crankshaft counterweights and the use of a windage tray will reduce drag on the crank.
The scientific use of coatings can also gain small amounts of horsepower.
This is just a small sample of the possibilities.
Each technique by itself won't gain much but done together as a package will easily gain 10% or even more.