supporting engine in car without 904 transmission installed?

Hey my mopar brethren and sistren,
is that a word?
Anyhow, I need to know how to support an engine (360 magnum) in the engine compartment (1968 Barracuda fastback) without the transmission mounted up and still be able to roll the car back and forth. It might be a while before I get the new tranny back and I want to get this old 318 pulled and up on the stand to pull apart. Being the motor mounts are at the front of the block I'm fairly sure but not 100% that I cant leave it supported only by the motor mounts. Any ideas? Thanks in advance.