Hmmm..seems like it very much like this site which claims it has vin decoders.....but basically takes them from people who develop them elsewhere and combine them into a site.
In case you didn't know...that's the vin decoder from this site which is already done.
They typically work fine as long as you dont have any of about 4 other different versions of ways to decode vins for these trucks.
I know how to do really any version related to these trucks, but not much at doing pages for basically entry type decoding formulas...so hats off to you there.
http://www.vehicleidentificationnumb..._decoding.html