The frames are virtually the same. Body mounts, rear floor mounts and the gas tank mounts are different. The 1949 frame will have the knee action shocks and mounts and the 1951 and later will have the tube mounted shocks and brackets.
I am using a 1954 GMC Suburban frame on my 1948, virtually it is the same. to use your pickup frame, you will need to borrow the body mounts from your suburban frame. You will also need the gas tank mount. The Suburban/Panel frame has different mounts from the firewall back. The four between the back of the door to the kick up has the wooden blocks and are riveted to the out side of the frame. The four farther back sit directly on the frame with thin rubber spacers. There are 8 mounts in all, 4 on each side.
