new T bar

ok so I put in the new torsion bars in the 69 barracuda. I need to move car. the shop manual says not to tighten up and front suspension parts until there is weight on the car and frontend height is adjusted, what's considered weight, I have a block and 4 speed in it right now to gets parts list bought and align things back up. is this enough weight to adjust height. I know I will have to do it again once a complete motor is built and put in place

You are ok, if you want more weight in the car, get your wife or friends to seat in it then adjust the nuts for your ride height.

From what I have read, the reason they are saying that is that you don't want to tighten things up with the suspension drooped, then put weight on it, because it can damage the strut rod and lower control arm bushings. Tightening in the unloaded position, then dropping the weight on them puts a lot of stress on the bushings that can't move. You want everything in its normal road position and tighten them there, so they are centered in the travel range and not overly twisting those bushings.

Same thing for adjusting ride height. I'd imagine it's a good idea to loosen those before making major adjustments, then tighten them back up.

If it were me, I would just set it on it's wheels and snug them up to keep everything in place for now, because as you said, you will be resetting everything once everything is complete anyway.

Yep put your biggest friend in the drivers seat and someone else in the passenger seat that way it should be level with just you driving it. after it's level tighten all the nuts.
When I worked in the alignment shop we would put the driver in the car if he was 300 lbs and align it.

I just eyeballed it when I put mine together. IIRC the main one of concern is LCA if using stock type rubber. If poly, I don't think it matters. It was a long time between my suspension install and alignment. Car was moved many times before I had all the glass in and bumpers on. Finally set ride height and torqued LCAs and strut rods about 3 years after suspension install, just after it got new tires. Was following spring till it went for alignment and finally got on the road.

For tightening the control arm bushings and strut rod; yes.
Do it this way.
1. using the t-bar adjusters, set the factory ride height, or whatever your target is. (If its a fish, its 1" something).
2. Tighten your bushings.

Once heads, intake, fluids etc are all done, reset your ride hieght to the same or close to the hieght you used in number 1.
Arm positions will be the same as when you tightened everything.