Lonny,
I used an outboard attachment on my Delta Top Turn lathe.  It allows me to turn items up to 33" diameter.  When I first put the roughed out block on my lathe and turned it on, it was so unbalanced that my 400 pound lathe jumped across the floor.  I had to screw on pieces of steel on the back (like tire weights) to balance it out.  Then I turned one side and flipped it and rebalanced it and turned the other side.  The more I turned, the better it got.
Zulu