HELLO FROM CARLSBAD CALIFORNIA..I DONT HAVE A FIAT 126 BUT I DO HAVE STEYR PUCH CARS... AND STEYR PUCH MADE A PUCH 126. WITH A STEYR PUCH 650 AIR HEAD ENGINE BOXER STYLE.. THEY ARE QUITE RARE. AND LOOK THE SAME AS A 126 . THESE ENGINES WILL FIT ANY 126 FIAT WITH A LITTLE WORK.. AND ARE OFFERED IN BIG BORE VERSIONS. UP TO 960CC TWO CYLINDERS. THESE ENGINES ALSO WILL ADAPT TO A NORMAL FIAT 500 LEO