Interesting variation on a very rare truck.. I have a '64 C10 extended cab pickup that started out as a C20 that was originally built at the Fremont, CA Chevy plant. I have no idea who the company was that did the original body modification on my truck. I would appear that they took the concept to a higher level using a combination of the rear portion of a suburbon blended with a pickup large window rear cap, resulting in a nice looking extended cab. The chassis under my truck was originally a dualie with a six foot flat bed. I purchased a '98 Z71 extended cab pickup, harvested the chassis and 5.7 V8, 4L60 trans and ten bolt rear end. The long chassis grave me enough length to accommodate my long cab and a stock '64 fleetside pickup bed. Wm.