Nothing on the C4ARM but, I have this on the differences of the applications:
Ford T10s used two iron main case configurations and both main cases are 9 1/2 inches long. The early, narrow transmission mounting bolt pattern T10 B-1 case was used from 1960-64 with 221/260/289 engines that had 5 bolt blocks and the later T10 H-1 case with a dual mounting bolt pattern entered service in late 1964 for use with the 289 and later engines with a 6 bolt block. A late T10 H-1 main case will fit a 5 bolt engine bell housing because it has both set of mounting holes, the early (narrow) and late (wide) pattern, but the narrow pattern T10 B-1 main case does not bolt to a stock 6 bolt Ford bell housing because none of the mounting holes line up. Two light weight, aluminum main cases were used in high performance applications. Lightweight 427 Galaxie/Thunderbolt/289 Cobras used a narrow pattern T10 L-1 aluminum main case and the 1965-66 Shelby GT 350 used a dual bolt pattern, T10 M-1 aluminum main case. The 260 and 289 Cobras originally came with 5 bolt bellhousing engines and used the narrow transmission mounting bolt pattern except for a handful of late production factory automatic Cobras that were equipped with 6 bolt engines. The correct iron main case for a 260/early 289 Cobra has casting number T10 B-1 in raised letters on the passenger side and the correct aluminum main case for a mid production-on 289 Cobra has casting number T10 L-1 in raised letters on the passenger side. Ford T10s used 6 different tailhousings with various shifter locations and 3 different lengths. The Galaxie/260/289Cobra tailhousing measures 17 3/8 inches front to rear and the casting number is in raised letters on the passenger side. It is T10 B-7 for the iron tailhousing and T10 L-7 for the aluminum tailhousing. The shifter mounts to the tailhousing with 3 bolts in an "L" pattern with the vertical part of the "L" toward the front of the tail housing. The center of the top front bolt hole for the shifter mount is 4 1/4 inches from the front of the tail housing. The shifter assembly is a 1963-64 Galaxie/Fairlane T10 unit with a shorter handle. A Mustang, Falcon or Comet T10 tailhousing is 3 inches shorter than a Cobra one and the shifter is not in the right location. The 1964 Fairlane T10 tail housing has the correct shifter location but, except for the Thunderbolts, it is 1 inch shorter, making the Cobra driveshaft to short.
