trying to identify my chassis

[jus_1982]

since buying my 70 longbed a few months ago, i have been doing research to find out what all i have got. i noticed something interesting when i peeked under the front end of the truck. i saw all the mounting hardware for leaf springs, yet it is running on independent suspension. does anyone have any idea if these came from the factory like this, or does it sound more like a 4x4 converted to two wheel drive. i found the id number on the frame up by the driver side motor mount. is there a site online that i can use to find out the history of this frame. i am a little lost and worried as my truck hasnt hit the road yet. if any one could help that would be appreciated greatly. thanks.

[1969k10stepside]

does the rear have coil springs? The frame is not curved on a 4x4 like the 2x4 under the bed,Ill get a pic tomorrow