Today I tackled the steering Rag Joint.
The ones on 79-80 were plastic and fall apart, bad design. Mine fell apart after 30 plus years. Took a total of about 3 hrs, I took my time. I will post pictures first, then I will follow up with what had to be done.

OK... 1st of all the car needs to be off the ground, ramps lift etc. The proper Part number for this is: Help Line Dorman Part# 31000. This Rag Joint is 2-1/4 inches
center bolt hole to bolt hole.  #1 remove coupler bolts at shaft. #2 remove upper shaft bolt at firewall. #3 Tap coupler at rack spline to loosen off shaft. #4 spray shaft upper with a good penetrating oil at slip spline. #5 sometimes need to tap upper shaft out of slip spline. see pictures of spline in vise,take car to mark your steering shaft ,have wheels straight. Drill out the 2 riveted post from lower coupler( in picture ) Bolt on Dorman Kit #31000 has instructions ,reused hardware with new bolts. #6 Loosen Rack front 2 bolts, and move rack forward to allow rebuilt shaft room to reinstall. #7 please note that the upper shaft at the firewall is (u-shaped) on on side at the end and must be installed matching this way. #8 Make sure to clean and lube shaft upper ,and lower rack spline. #8 Line up re tighten 2-rack bolts ,then all others. Drives like New! Hope this helps.....Kirk