I wouldn't do it... Flex plate can flex, oil may go everywhere causing it to be of balance... Stick a transmission behind it - just make sure it's in nuetral and you run a hose or steel line between the two cooler fittings.
Yep, and aren't there things inside the torque converter that rattle around just a bit when the transmission isn't hooked to it? Taco about out-of-balance and shaking around.