Getting ready to swap a 5.7 into my 73 Dart Swinger

I have looked thru this thread because I have wanted to put a 5.7 with a 6 speed automatic transmission into my 68 Dart. I found the 2012 combo at a swap meet. I had hoped that this had been done enough times already that there would be easy to find info to complete this. Apparently that's not the case.