Why not get the stroker in and run the car a while with it before you tear it down for paint? Nice find! You are really gonna like the power those strokers put out. I just ran my 416 for the for the first time yesterday. Had open headers cause I did not get the TTI X-pipe and the one I got from Jegs won't work.
You also need to consider the fuel situation and if you are going to use elec waterpump drive and elec radiator fan. Is the engine going to allow the use of the stock hood?