Will ford 400 engine fit 300 6 cylinder transmission?
No, a Ford 400 cubic inch V8 engine will not fit a transmission designed for a Ford 300 cubic inch inline-6 engine. The bolt patterns, bellhousing dimensions, and overall size are completely different. You would need a transmission appropriate for a Ford 400, such as a C6, FMX, or Toploader, depending on the year and application.