The WRX/Forester XT ones. Nothing too extreme, just to make the engine more resistant to the higher power output.
The pistons are stock.
GP Perfomance owner Patrick shared his experience and said they should be fine with builds around 360 crank HP. They can handle more (also very tune specific regarding the torque wave in relation to engine speed) but should be fine, all day long, hovering around the 360 mark.
That's unfortunate
Wish you a speedy recovery
