[larry davis]

I just finished re-attaching my front
sub-frame to the body of my 78 TA.
This is the second frame off I've done to a 2nd gen TA. Just jack it up & place the front stands as wide as you can on the forward transverse floorboard stiffener. This assumes you have removed the engine & all the front sheet metal down to the suspension. The rear should be supported at the extreme rear frame rails (assuming your removing the rear suspension).
Once all the front suspension components are off & all the brake / fuel lines removed, all that is holding the front sub-frame is the four rear mounts. Spray some WD40 on them & let soak, then break loose w/ breaker bar or impact. It's best to have another set of hands to help manuever the sub-frame when you take it loose! I use a high lift floor jack w/ a 2 x 4 across the saddle that cathches the sub-frame just rear of the lower a-arm mounts. With the other person operating the jack and applying wieght on the front horns of the sub-frame loosen the bolts and lower it to the floor.
The sub-frame on f-bodies isn't too heavy, I'd guess @ 150 lbs. you can lift it but it's awkwards.
From here you remove the entire rear suspension as an assembly.
Provided your car has been stripped of all the attachments, etc... it should not "flex".
Reassembly is alot trickyer as to avoid misalignment and not preloading the frame you must reassemble the front sub-frame, then realign & tighten all the mounts with the weight of the car on it's suspension accordingly. I do so w/o the enginge, trans, & front end components. I haven't had any problems w/ this procedure.
Just be sure to use six good stands & exersize common sense caution. You'll need the extra two to position under the front sub-frame & rear during disassembly.
It's easier (& more expensive)to let someone do it all but not near as gratifying to be able to say "I did it all myself"!

Good luck!