I know this is an old posting, I haven't been on any forums in a long time.
I have purchased a "E Z Chassis" kit just before Thanksgiving for my '58 short bed. Will be using a '86 C 10 long bed donor frame. My project is setting outside as my shop isn't finished yet, so I'll waiting until warmer weather to start.
I've already asked several questions via email and the owner, Ed Lipinski has responded very quickly.