hey Mark, you're the one with the details
all that number can tell you is that it's a 57 truck assembled in Los Angeles, the rest of the number means it was the 6,070th one from that plant
the 'frame number' is an incomplete part of the ID number [vin or serial number] that should be on a tag on the drivers door post, a 3100 would start with "3A" [114" WB] - if it started with a "V" it would have been V8 equipped, other than that numbers can't provide any real detail
Bill
