I just installed a SYE and CV driveshaft on my jeep wrangler a couple of weeks ago. I didnt have adjustable lower control arms, but I did have adjustable upper control arms. I pretty muched eyed the angle of my rear driveshaft in comparison the my u joint cap and adjusted my control arms accordingly. I know I should of used an angle finder, but I haven't had any vibes or issues yet.
here is a site that might help
Pinion Angle Alignment - 1