 Two more cars with the original spider body style were built fitted with a 3,495 cc, cast iron block, double overhead camshaft straight-six engine from the contemporary Alfa Romeo 6C 3000 CM racing car in place of the all-alloy four-cylinder; one was dismantled soon after its construction.Thanks to an output of at , the 3.5-litre Disco Volante could reach a top speed of .The spider and coupé 2.0-litre prototypes are preserved in the Alfa Romeo Museum in Arese, and are regularly used in classic car races.