They are definetley Ross pistons. They were custom made in the Ross factory for most likely Probe Industries. I have had a bunch of customs made through Probe and the BB Mopar pistons allways had the Ross machined off. They did forget once and I got them with Ross not machined off. As far as what they fit, a micrometer or at least dig. caliper could measure bore size and comp height. They look like they came out of a motor that had a bunch of debree from spun bearing or a flattened camshaft. My