60-66 frame differences

[lswonmatt]

I have purchased an extra long bed frame for parts but it is a nice frame so since I though about cutting down a long bed to a short bed can i figured it would be easier to do the work on the frame and swap all my cab engine trans and front dog house over to the frame once i finished... Im pretty sure it's a 65 frame and my truck is a 66 gmc but is there any way I can tell what year the frame is or is there any big differences between the 60-66 frames that i could look for to identify if it would work or not