1941 Pickup frame repair

[burly]

The rear uprights on both sides of the 1941 6 cyl. half ton pickup all but rusted into. I have a 1940 frame that was hit in the front and warped but the rear 1/2 of the frame is perfect. Have any of you guys ever attempted to splice two frames together? If so where would be the best place cut and weld back together? Would you cut the sides and the X member in the same location or stagger them? Appreciate it fellas!