Need help with short conversion for my 63!

[Isaiah92260]

I've trying to research but I mostly see post about guys doing this on the 67-Later models, and the ones I see for 60-66 or very Vague Details or just dudes showing off their work but no details.
Anyways me and my welding buddy are very close to cutting my bud, but I need to do my research about cutting the frame and the measurements for the bed, does anyone have info they could share with me so I can cut it??? Please, and thanks guys.