Hey Mark, thanks for the welcome. I stand corrected on the mounts. I was looking at it from directly a "bolt in" application with no welding or fabricating. I have heard of quite a few people performing the mount swap that you did, with no problems.
I took the easiest and cost effective route for me.
Yes, I am one of the original members of Astrosafari.com, actually I am one of the original members of the old Astro V-mag site before it started having so many problems.
I have not yet delt with big block astros, but have seen quite a few done. As far as the engine cantilevering over the stock v6 towers, I have not noticed any problems. Of course, I built mine for towing, not high power, so I don't know how a high output engine will be affected.
I do know that the swap is very easy, because, depending on your setup, you use most of the original parts off of the v6.
Thanks again for the welcome, I'm sure I will learn alot.