Both run all the way through the shank. That's designed so you can use it whether it's in the vertical or horizontal mounting position. You can install it inside your trailer hitch receiver just like this or you can flip it to this position here and still install it inside the same hitch. You can use it in either the horizontal or vertical position. The shackle is removable. This portion right here is just like a large screw.
For your 2004 Chevy Avalanche the Rhino Rack roof rack part numbers # RREB137B, # RRRLKVA, # RREB-FK1 and # DK227 has been confirmed as a fit and would work well. Your sunroof wouldn't be an issue either. I would recommend keeping it closed since it will be very loud transporting a ladder up there from the wind noise. However, I have a better solution for you in terms of a roof rack for securing a ladder. Instead I would recommend the Rhino Rack HD bar roof rack part numbers # RB1375,...
Those pins are debatably fine for towing, if they are the right strength. Grades of bolts basically indicate their hardness and therefore tensile strength. Grade 2 (normal cheap stuff) you can bend a few times and still have a viable bolt for holding a picture on your wall. They're pretty soft. The one thing they don't do well is high tensile forces. The soft steel will either strip the threads or literally pull the fastener apart. Grade 5 bolts add a significant amount of tensile strength but can still take side loads with composure. They will bend a decent amount before breaking. Grade 8 bolts are very high tensile strength. They are best used in applications where their entire load is tension. They don't like to bend. I used to use grade 8 bolts through a chain link to hoist engines until I lost one. I had a grade 8 bolt threaded in the whole way into a head. It didn't bend a bit before shearing off flush with the head. I won't talk about the brand new polished aluminum oil pan or $400 radiator that bit the dust in the process.
Another safety note is to weigh down the strap or winch cable, (especially a winch cable.) The reason is that if it was to snap the ends would whip around violently, injuring anyone in their way. A heavy blanket thrown over the strap or cable will do the job. Alternatively, if your recovery accessories come in a handy bag, fill it with something heavy and suspend it from the strap.
Pulling double duty is RBP newest hitch shackles. These unique designed hitch receiver includes a shackle built right in, so you can pull and tow without having to remove your hitch cover! These will fit any 2 inch receiver and look great as well. Add a 3/4 inch d-ring for added towing! The RBP hitch shackle is rated for 9,500 lb's of towing capacity, and are made from high quality, heavy duty steel construction. The RBP hitch shackles connect to cables, tow straps, chains and other things to pull your buddy out of the mud.
There are plenty of great parts to choose from when you buy from 4wheelparts.com. You find recovery hitches from a wide range of brands, including Warn, Rugged Ridge and Factor 55. To get a sense of which hitches work best for your Jeep, you simply need to input the pertinent information into 4 Wheel Parts.com's search bar to automatically see the results.
Nice Shackles as described, though not really any different than any other shackle, except it says Rhino. I paid extra to get these hoping the powder coating would keep them from rusting. First rain, not ever having been used, rust appeared in the eye hole. They should ecoat, with a zinc phosphate pretreat, then powder coat to make this a great product. Military surplus may be a better option, and paint over the CARC.