I spent a lot of time trying to figure out the best pistons to use. As with anything especially pistons, valve springs, and valves themselves in my experience certain models and manufacturer periods seem to have a lot to do with the quality. Look at Toyota engines right now compared to 20 years ago. Anyways for hot lake motors more recently speaking S&F community here likes WSM and Vertex pistons the most and anything planned to run over 7000RPM its recommended you send them to John Marles for top pinning and your good to go up to 8000 or so reliably. For a full tilt race motor Wizard pistons are the crowd favorite.

In my build I ended up using Wisecos for three reasons; 1. I know they are tough as hell ive used them in the past 2. The price my machine shop got me on them was great, cheaper than all other options at that time 3. My machine shop guy has built a lot of Merc V6 stuff and said these were what he recommended so that was it. A whopping 8 hours on them so far so good.