Just move slow and take your time, You can leave the drivetrain in the chassis,but, it will make blasting/painting the frame hard. I ran into clearance issues with the rear tires on the way out from under, so I just removed them and lowered the jack and let it do the rolling. Safety first! have plenty of room to work,plenty of blocking and jackstands. You will have LOTS of wires,cables and lines to unhook!
79 elcamino SS454 tribute car in progress