THE PISTONS LOOK MORE LIKE THEY HAVE A HOLE IN THEM FOR A PISTON TOP.HAHA ANYWAYS THE ARE OEM REPLACEMENT PISTONS FOR A 1975-78 460 JUST .060 OVER. THE 460'S SUPPOSE TO HAVE 8.6:1 COMPRESSION AND THE 1969 429 IS SUPPOSE TO BE 10.5:1 COMPRESSION. AFTER THE HEADS HAD TO BE MILLED 8 THOUSANDths I JUST GUESSED THAT I WOULDNT BE ABLE TO RUN THE 429 ON PUMP GAS. THERE IN I THOUGHT IT MIGHT BE BETTER TO PUT THE ON THE LATER 460.