Need Help building a 400 for my 68 plymouth valiant

I was going to take it apart and inspect it. I still need to get a oil pan and fill tube, tranny, engine mounts, and headers. Its going in my 68 valiant. I know its pricey. But your right cause if it looks good I was going to put the ported 906 heads on it and see how it does for now than once I get the parts Than I will take it out again. I have tons of time so im just looking at my options and learning on what to do. Thanks