Originally Posted by 496CHEVY3100
Strange this was posted today after our conversationm.
Glenn Sparks Box frame or calif.frames were made primarily by A.O. Smith Company for G.M. They are seamless and about 70 lbs lighter than the other.Non box or Cailf.frames can easily be spotted by the welding on top where as the other is a seamless piece of tubing with no welding on top....also the rear shackle hangers are welded on the tubing frame as opposed to riveted on the other...the front end part of the frame where the suspension is primary the same on both and swegded onto the box frame and welded....The term Cailf.frame comes from the fact that G.M.shipped most of them to Calif assembly plants due to freight cost were less due to box frames were lighter ..times millions of frames shipped. ....i have several of each....by the way only tubing ....box frames were used to build the Famous Black Widow Race Cars in Atlanta. ..according to my freind Rex White nascar Hall of Fame inductee who built and drove the cars for G.M.....
Hope this helps ....also we used many box frames to build dirt track race cars due to the aforementioned lightness and strength. ..sorry tri five lovers
That GM factory was in Oakland just North of me. A few years later they opened the Fremont factory where I live, and where my Buick GS was born.
Edit: I just did a little research on the plants, Oakland opened in 1916! And it ran until 63, I didn't know that, with the Fremont plant opening in 62.