[jonzcustomshop]

VIN Format: 1965-1971 GM
Decoding: 136806K116417

1 Mfgr 1 Chevrolet
2-3 Series 36 Custom El Camino V8
4-5 Body Type 80 2dr Sedan Pickup
6 Year 6 1966
7 Plant K Kansas City/Leeds MO
8-13 Sequential Serial # 116417
Serial numbers start at x00001 (100001, 500001, etc, depending on plant)

I got this with the vin decoder...
any chance you have a pic of your vin?
it should be above the driver door, and also on the top of the lh framerail under the alternator, in front of the control arm.
a 66 truck vin should start with c, and then be followed with a 14 (swb), or a 15(lwb), and then a 4 (pickup), and then a 6 for the year, that will be followed by a letter for the production plant, and then the 6 digit sequence #
the frame should just have a 6, the plant and sequence #