theres one guy on here that used milk jugs, a section of pipe and some jack stands... hung the motor on the pipe supported by the stands on top of the crates, then inched the frame over.
http://forums.sohc4.net/index.php?topic=71240.0other than that, set the motor on its side with lots of padding underneath, lay your frame down over the motor, bolt it up and then pick the bike up. this seems to be the most common way. don't forget to tape the crap out of your frame!!
what color green is that, and was it painted or powder coated?