So, I have 83 300sd, California car I got from someone in May 2013. I started out replacing fluids and immediately drove it cross country for work about 10,000 miles in a few weeks, and it proved itself. I then installed stereo, replaced the belts, motor mounts and fuel injector seals/gaskets, and did the lower ball joints.

The main problem is it's never been able to get aligned, and definitely it's due to worn rubber that's way past due. It is my daily driver and it has still made a couple cross country treks in this condition, but I put it out of service for winter due to confidence in handling and salt.

What I want to do now is overhaul front end so I can get new tires and an alignment. The guide rods are real bad. So on the list is; upper control arms, guide rod mount and ball joints, eccentric bolt, lca bushings, tie rods, center link, idler arm bushing, steering shock, and new shocks.

What I'm unaware of, is what to do with the rear end. It sags considerably, and I know there's the differential mount bushing could by worn, but the whole sls system, seals, and everything else could need work too, and new shocks. Could be a whole other project, if I do the front end and pay for alignment, would it be wise to do the rear end too or could it wait so I can have my driver back?
Any tips for inspecting the rear end suspension?

Also on the list and unrelated this car needs breaks, and that means I need to get a pressure bleed kit, and I'm going to fix an oil leak from turbo drain tube, valve adjustment, fix air cleaner mount.

The last thing I need to address, it's alternator, the replacement didn't have enough room to pivot and tighten, I got a friend to weld a plate that has since broke. Could the alternator mount/pivot plate be ordered, or does it need to be pulled from junkyard?

I appreciate any tips and info, without this forum I wouldn't be attempting such an undertaking but I love this car, and get a thrill out of keeping it on the road as daily driver when it is older then me. I'm away from home (truck driver) so I'll add pics when I get there but was hoping to order parts before I get there...looking at 1500-2000 in parts to keep this car alive and well.