Does the transmission pull straight off the engine?

[Smallblock454]

Hello,

i think that will be difficult, if the nose of the car is down. Would be much easier if the car is leveled.

You need definitely to support engine and transmission to get the transmission out. When you say the hole drivetrain moves, how did you support the engine? From the top via chains?

Try to support the engine and the transmission from the bottom too.

Also recheck if all bolts are loosened.

Regards, Markus