1993
I'm looking for the date of a J.C. Higgins bicycle with the serial number 705495
DO3174
2530677
1942
Based on the date code for the letters in this serial number, it was made in February of 1975.
January 1989
Contact specialized.com website.
1987
Serial numbers aren't coordinated between manufacturers, so you've got to know that first. Then maybe you can find out some more.Westfield Bicycle Company
You can usually find the year of a Huffy bicycle (I believe they were the only manufacturer of West Coast Choppers bikes) by combining the first digit of the serial number with... some guess work. The first digit of the serial number equals the lastdigit of the year. So... if your serial number starts with 6, then the bike could be made in 1986, 1996, or most likely, 2006 (this is where the guess work comes into play). Considering they started making these bicycles in 2005, this is a pretty reasonable assumption.
You don't, as the serial numbers aren't coordinated between manufacturers. You've got a better chance by posting a pic on a bicycle site(www.bikeforums.net, www cyclingforums.com) and ask there if someone can identify it.