Never mind

The Summit listing for the KB399 pistons states in the "check fit" that they fit the 5.2 Magnum engines.
I would never build an engine with any websites claims that anything will fit without checking myself first. Any piston with a positive deck height should be checked and never assumed to fit. Case in point the current small block I am assembling has been decked to zero a stock 318 piston. How much do you think they took of the decks?