Look around over at
www.nissanminis.com there are several v8 swaps running around over there. You could also look at
www.4x4parts.com discussion board as I'm pretty sure there are a few 4.3 and v8 swaps there as well.
There is a manufactered mount kit available for the SBC but I'm not sure where. Just check those sights I'm sure someone will help ya out.
