64 gto with original engine and m-20 and cant figure out if rearend is original. Manifest says its 1-2-K in boxes 69-70-71. Rearend has 9788647 stamped on lower right corner of pumpkin webbing and GFD stamped on lower left corner of pumpkin. I do know its a 8.5 10 bolt from pictures on other sites. Cannot find any other numbers except a G and upsidedown 2 on drivers side axel tube. Tags and stickers and colors are long gone. The whole rearend is red primer in good condition but trailing arms etc are typical midwest rust. Any help? Thanks!