Another unorthodox method...
 

When not on the stand, I support my engine on an arrangement of rubber cushions, located at several points on the underside of the case.

http://forums.pelicanparts.com/uploa...1082132326.jpg
Discussed in this thread:
http://forums.pelicanparts.com/porsche-911-technical-forum/145598-unorthodox-engine-drop-into-hole-pics.html

They're made from rubber mallet heads, cut to various heights as necessary. The first version of this device was screwed to a wood base, but I later attached the rubber cushions to a steel plate by inserting them over little steel studs welded to the plate. Can be rotated on the cart if necessary. Very stable and engine friendly, and takes the weight off the heat exchangers.

Here's the steel plate version without the rubber inserted:
http://forums.pelicanparts.com/uploa...1082132553.jpg

More pics and details available.