Would it be fine to install lowering springs/shocks several days before the rest of my parts come in? (PHB/TA/LCA) Should I just wait and do it all at once, then get an alignment?

1.25 inch lowering springs.

 

I would wait, your gonna need an alignment after installing the springs, then the rear will have to be tweaked after installing all those parts and I wouldn't go a week with out an alignment after an altitude change, I did this to the front tires of one of my old Hondas in 1,000 miles time after lowering the front end and not getting it aligned right away.

if it was the other way around (installing all the rear control arms and PHB stuff then springs and shocks next week, sure thats what I'm doing RIGHT NOW).

 

it will be absolutely fine, you will have no issues whatsoever driving for a week unless you're running really wide or weird offset wheels

 

i will be doing the samething here in about a week i have heard if you do the lowering springs you might have to adjust the torque arm pinion angle? is this true

 

If you are talking a matter of days, then yet you will be fine. Your car may pull or drive a little strange, but it will not hurt anything to do so. The biggest concern when lowering a vehicle is drivetrain noise caused by the change of the pinion angle. You will most likely notice a vibration at cruising speed/deceleration, but it will smooth out under acceleration. An adjustable torque arm is recommended to correct this

 

I'll have to Agree.
It's not a issue unless, "you're running really wide or weird offset wheels".

 

Would LCA relocation brackets do the same thing??

I have those (not installed yet) and that should bring the axle back to center within the wheel well and keep the pinion angle the same (after lowering)

at least in theory

 

Lowering my car had no effect on the rear....it was exactly the same as stock height. Only time I had to re-center is when I installed a 9". I

 

NO, lower control arm relocation brackets have NOTHING to do with the pinion angle, they are about getting the control arms level with the body to prevent wheel hop, the torque arm is the only location on the rear end that has any control over the pinion angle as it is what controls the rotational angle of the axle, control arms arm for the offset of the axle front to back.

 

Daniel is correct. The only way to correct pinion angle is with a torque arm. Some people try to use a non-adjustable torque arm and use adjustable lower control arms as well. While this will technically work to correct pinion angle, it will also change your wheel center and instant center geometry, and puts a lot of preload on the torque arm.