Rear Axle drum to drum width:
NOTE: These width dimensions where measured with 1940 style brakes. Mechanical brakes may differ.
Year Width Spring mount eye to eye
1928-1931 57.0" 49.5"
1932-1934 57.75" 47.5"
1935-1936 59.5"
1937-1941 59.5" 48.5"
1942-1948 61.0"Stock Axle length
Year Length Number of teeth
1928-1931 32.09 24
1932-1934 32.18" 18 (use 12 tooth spiders)
1935-1938 32.85" 18 (use 12 tooth spiders)
1939-1941 32.85" 16 (use 11 tooth spiders)
1942-1948 33.70" 16 (use 11 tooth spiders)U-Joints
Spicer # NAPA # Dimensions
1310 210-0153 3-3/16 x 1-1/16
1330 210-0213 3-5/8 x 1-1/16 or 1-1/8
1350 210-0178 3-5/8 x 1-3/16
Combo joints
1310-1330 210-0134
1310-1330 240-0356
1330-1350 240-0448
1310-1350 240-0358MPH = RPM * Tire dia (inches)
trans final gear * rear gear * 336