Removing the tranny crossmember

I think the only way I can wrestle the tranny pan/downtube off is with the crossmember removed.

Anyone done this? Will a floorjack with a wood block under the engine be enough to support the whole deal? Or am I courting disaster?

Also (1) Is RTV gasket goop enough, as suggested by DC? Or....
(2) Should I get an actual gasket? And where can I buy just a gasket alone?
(3) What's the best place to tap the pan for a temp sensor?

Thanks in advance.

i have removed the x member off of my 87 cherokee to replace teh trans mount. its not fun to reinstall but very doable with a floorjack holding the tcase up. just make sure you get the it put back right... i tried putting mine in backwards and it didn't like me to much... kept fallin on my head!