383 engine & trans mods.

Hi everyone, Having just joined the site last night & seeing how much technical knowledge there is to tap into here, I am wanting information on what I need to do to install a 383 & 727 transmission including driveshaft modifications in my 72 Dart. It originally came with a 318 & 8 1/4 rear end. I believe it has the 803 transmission currently. Will the current rear end hold up to the 383 or do I have to go to an 8 3/4? I don't plan on really driving it hard, I just want to know it's there if I want it. The engine I plan on using is from a 69 Road Runner & has a set of Jardine headers. Other than that it is bone stock. Any & all information is greatly appreciated. I'm hoping that someone out there has done this swap before & can maybe save me some time & heartache if I should miss out on something important in doing this. Thanks so much, Eddie