Stepped piston hitting head, options and advice needed.

Sure does look like the KB356 illustration:
KB Hyper Piston - Chry 408 Rod 6.123 Quench Head 23.5cc 2V [KB356] - $462.70 : United Engine & Machine Co. Incorporated, Performance Pistons

Looks like the EQ LA heads setting on it now..... hence the thread.