Can Somone Identify My Two Frames?

[Clavo106]

I had two frame with Questions and concerns. both are Sub posts to be 1/2 ton frames. 1970 closest to me and furthest is 1971 (in photo). in my 1970 frame at some time it got 3/4 ton suspension. the frame matches the vin. and the cab mount are in location for 1/2 ton. now the past owner was driving truck with out springs. the shock where the only support for a un given amount of time. the frame and the axle tubes did not look damaged but the vary back where the spare tire mount and back looks bad, i believe very heavy loads.on the bumper (the truck came with helper bags)I was going to cut and replace the back portion.
Now 1971 I bought for my concerns. got it at the wrecking yard .I believe its a 1/2 ton. the vin read 1/2 ton. its exactly the same accept it did not come with a steering links, p/s box and axle when I bought it /.the owner kept the cab with the fender read c/10... now someone cut it I believe at one point? but the cab mount are way lower and welded on (like it would be in location on the 3/4 ton) there not even straight up little off. the cab look straight at the yard with cab bed and fenders? now on not Shure what the back side of the frame is. (The White spray paint is what on confused on) I don't c that brace gong to trail arm member to the frame. on any other c10 or c20 frame? and the D/shaft support bearing mount not Shure if that correct it looks homemade.
Im right now in the process of doing LB to SB conversion on both.. not Shure what frame to keep because one just a parts truck. im thinking repair my 1970with matching vin even though I have to change suspensions around and fix the back frame / but I need to cut 8" off the back any ways and a few more to fix the area on the rails.
Let me know anything u mite notice any advice works. thanks.

[ETsC10]

Your pics are missing! If you need help figuring it out, give a holler and someone will give you a hand.