My family stopped at the Automobile Museum in Tupelo MS. There is a lot of different cars there. I would recommend stopping if your in that area. One car that cought my attention was a 47 Chrysler limousine.
If your looking at an engine swap using gm you might consider a 4.3 V 6. It basically has the same internals as a 350 but is a little shorter than a 350.
I just thought I would give you another option to think about.