the diff in the back , the early has a shallow indent[ about 1/2 deep] and 3 ribs about 8 inches wide in the back, the later has deeper indent and 4 ribs in the back. [about 3/4 inch deep] the cab buck at the museum has both types carved in the back. the frame had a cross member with out the V channel going back to over axle.
Note the difference in the front frame crossmember too.
Posted on Oct 14, 2011, 7:34 PM from IP address 220.127.116.11