I’m using DSS -18cc forged pistons which put me around 9.2:1 with Speedmaster heads. My research showed that a zero deck height piston at 10:1 is less prone to detonation than an 8.5:1 piston sitting a ways below deck. I have tried the NHRA forged “stock class” pistons and do not recommend with boost. The piston crown caved in. I did also consider the trw pistons but decided against them again due to their below deck height and also weight.