Having installed a G body sub frame on my 54 using most of Frank's methods I can attest that it is very strong and looks good. The front mount for the core support does take a bit of thought as Frank's detail in this area is a bit thin. This is where I diverged. Also, the G body frame will require the bottom the radiator to be kicked forward to clear the steering box.
As to the Camaro/Firebird subframe, I think it is pretty straight forward and there are several sites out there that show it. Do a google on camaro, subframe and you should find most of them. Total Cost (TCI) also sells a video ($35) that documents this swap. I would get the video if I were to do this one.
As for subframe swaps I would suggest you fully consider other options such as an IFS kit. The cost of a kit starts around $1,350 and comes with everything you will need. They are very easy to install and the end result is much more attractive to future buyers. In retrospect I think I would have done an IFS instead but I did not know as much then as I do now.
It is your truck and your money so do what makes you happy.
