When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I don't believe you can tell options from a '66 VIN just the year and whether it's an FL or FLH. Here's a site that will tell you what all the letters mean etc. Most of the big twins sold were FLH's with the King of the Highway group (which was dealer installed) spotlights, turn signals and some chrome stuff. The FL's were mostly police bikes, both foot clutch and hand clutch. http://www.shovelhead.us/history/66.htm
Engine number is the VIN (Vehicle Identification Number) and is located on left case.
No frame number.
First two numbers are the year. 48EL5719
Letters are the model. 48EL5719
G , GE - Servi Car Side valve 45 cubic inch three wheeler, 1932 to 1972
E , EL- Overhead valve 61 cubic inch
F , FL- Overhead valve 74 cubic inch
K - Side valve 45 and 55 cubic inch
U , UL- Side valve 74 or 80 cubic inch
V , VL- Side valve 74 cubic inch made prior to 1936
W , WL,- Side valve 45 cubic inch made 1934 to 1952
Harley-Davidson Fat Boy Becomes a Dark, Decepticon-Inspired Custom
Slideshow: Killer Custom's latest build relies on styling changes rather than performance upgrades, giving the cruiser an entirely different personality.
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.