 In order to supply U.S. allies , much more production was required than was possible through the firms producing the M2 ( and the larger M3 Half @-@ track ) . International Harvester ( IH ) could produce half @-@ tracks but some differences had to be accepted due to different manufacturing methods and components . This led to IH producing for lend @-@ lease the M5 Half @-@ track as a M3 equivalent and the M9 as the M2 equivalent . 
