I have just finished my new lightweight frame. It is going to hold a Modernistic/Cub style tear 4 1/2 feet wide. The frame is a bolt together 2x2 1/8" angle with a 2x3 1/8" tongue. the torsion axle reinforcements are 2x2 3/16" angle. With all of the linear feet of angle, the tongue, nuts and bolts I estimate the frame to weigh about 127 lbs. as it sits without axle or wheels. I am not going to have it welded. The nuts are torqued and with Loctite. The floor will keep it square. I am basically using the frame suggested by Mike in the thread labeled "Lightweight frame building" Attached is a picture. You may also see the start of frame building on my Yahoo Photos accessed through the Hall of Fame under Jerome Guffey's 46 Kit.
Jerome