Bought my first classic Chevy truck... I think?

[Slemmy]

So...

I bought my first classic chevy truck. I can go into the romance of how I first saw her on the side of the road and knew she was going to be mine and yadda, yadda, yadda. But for brevity's sake I'm going to get straight to the point.

She is titled as a 1969 Chevy. She has a 396 engine in her. She's got a long bed. I'm trying to decode the vin, but the VIN plate and VIN number format doesn't match anything I'm reading online for 67-72 chevy trucks. Here is the VIN:

KE134Z111XXX
All numbers are actual minus the last three that have been substituted with Xs. I've attached a photo.

Here is the site I am trying to use to decode:

http://outintheshop.com/vin_decode.html

This VIN format doesn't work with ANY of the formats given. The closest would be the 70-71 GMC VIN DECODER, but there is a "1" on my vin that would need to be an "I" (to indicate 1971) according to this site. So now I feel like I'm going crazy. The steering wheel on the truck is a GMC and the door VIN tag says GMC Truck and Coach, not Chevrolet AND General Motors Company as I've seen on here.

Did I buy A GMC that's in disguise as a chevy? Everything on the truck is '69 Chevy (c/20 badges, '69 front grill and markers, etc.)

Can this VIN be decoded? I love this truck and I'd like to get her restored to her assembly-line-self. But I'm afraid I'll never know what that was!

Help!