This is Porterbuilt's new inner frame structure for the 63-72 C10, that is now in production.
This inner frame structure will have the integrated trans mount and trailing arm crossmember, which are both adjustable. It will include all your hardware and frame mounting brackets to install into the truck.
This will work with most transmissions, including the 4L80E.
Priced @ $995
Porterbuilt Inner Frame Structure:
http://www.azproperformance.com/Port...63-72-C10.html