If you have the standard comp ratio, how does a built 2.6 drive any different to a stocker? A bit of a tickle on the head and a set of bump stock can be done to a stock bottom end?How does a set of pistons and some rods allow the engine to make more low end twist?
Plenty of people making over and above 400 kW with the OEM engine. Simon from WA, Reaper here in NSW (470 kW using a 8374). If they "rebuilt it" with some Pistons and rods, how or why would the power delivery change? (Barring compression ratio increases)
If the engine is still healthy, leave it alone. Rebuilding a 2.6 is like buying a box of rotten bananas. It's a little cheaper but they are garbage.
2.6 = stock engine or healthy wrecker, built engine = stroker. Costs not much more.