as soon as u start to stroke an engine even a little bit its drops the life of the engine. Geez stroking it out to 2.9 litres..... tallk about paper thin.
You are confusing stroking a motor with boring a motor
If you tried to bore a motor out to 2.9 then you would bore right through the walls into the jackets
Mind you this can be done also if done properly - Top fuel racers etc sleeve all there blocks to maintain optimum bore thickness with there overly huge pistons but this method costs big $$$
stroking a motor is where you increase the distance between TDC (top dead center) and BDC (bottom dead center) on the crankshaft
as long as you compensate the extra stroke on the crank with either shorter conrods or repositioned gudgeon pins on the piston to make sure pistons stay in the actual bore betwen these distances you'll be fine
stroking a motor will not reduce the life expectancy of an engine as stroking by itself doesn't change the bore size in your motor