Murdoc,
Look up TRW, Silv-o-Lite, Federal. All make pistons both stock and high performance applications. I don't know of HP pistons for the 292 but a call to the above could produce some!
Cost of custom pistons can be expensive for little gain for street use.
Cast pistons in a 292 should handle anything you would build for the street. After all, the 292 is a "grunt" engine!
A 292 has potential to deliver more than grunt, supercharged @ 4-5 psi boost, 4 barrel carb, cam, head work(of coarse!) and a few other tid bits done to it dynoed 325 HP with cast pistons and it stays together! Not bad for a UPS truck engine!
