Rubber control arm bushings means
you'll be torquing the bolts that go through the control arm bushings with the suspension at normal ride height. GM calls this the "Z Height". Frankly, I think it's a mistake to not use Polyurethane bushings which can be torqued in any convenient position.
All torque specs and the "official" Z height measurement and measurement procedure are in the official GM service manual you should have.
"While you're in there dicking with the control arms anyway", you should replace the lower control arm bushings, the sway-bar end links, any loose joints such as tie rod ends, idler arm, pitman arm, LUBE ALL THE (steering and suspension) JOINTS, check the sway bar bushings, boots on the CV joints, shock absorbers, check the brake pads and rotors, and AT LEAST FLUSH the brake fluid and verify that the brake hoses are usable (rubber not cracked). Take a look at the rag joint on the steering gear, too.
When it was me, I blew the brake caliper pistons out, cleaned the pistons and pried the crust off the caliper seals with my fingernail, lubed the caliper mount rubbers, and then slapped the calipers back together without buying any parts--just cleaning what was already there. The caliper pistons moved noticeably more easily afterwards.
If you have non-welded alignment eccentrics on the upper arm, you'll want to at least make precise note of where they're positioned so you can put them EXACTLY where they were before you took them apart. Getting a proper wheel alignment would be even better, and pretty-much essential if you replace any of the tie rod ends.
If your eccentrics are welded like mine are, you can choose to cut them free or leave them the hell alone. I left mine where they were. "Alignment" then consists of nothing more than adjusting the toe, and thereby the steering-wheel straightness.
https://www.gmt400.com/threads/front-end-overhaul.45214/
All of it's good, but especially beginning at Post 24.