What’s the big priority to swap on rear DISK brakes anyway?
Unlike most other other sheeople, it is very unlikely you will ever see me ditch the rear drums on either of my old rigs and move to rear disks. I could think if a thousand other things I could and would spend that budget money on over and above a rear disk brake swap. Totally unnecessary swap for 90% of us IMHO.
In one of the posts on page #6 the OP said the drums he currently has (I can only assume those on the 14-bolt) are "a rotten mess" so to bring them back to a reasonable state of reliability (which to me would be like brand new) he'll be spending some money, at which point he may as well spend said money on the disc swap. Which makes sense to me, to a point. See, I tend to agree with you that rear discs are usually more of a "want" rather than "need" upgrade, if it's even an upgrade to begin with - honestly when I see 3/8"-thick brackets with no additional bracing I feel quite uneasy running them. Why, well cause we're at almost 7k on the rear axle, with a maxed-out Saginaw pump and hydroboost during a panic stop those calipers will clamp on the rotors so hard that the caliper bracket is gonna scream for mercy. Maybe it will survive the ordeal, maybe it will take some damage, I don't know and don't particularly care to find out. And maybe in a light vehicle like a Blazer (or a Bronco, cause similar setup is available for Ford trucks as well) it won't see such loads and maybe it is perfectly safe to use - again, I don't care to find out the hard way. I'm aware that there are many people out there who run these things day in and day out no problem, but if SHTF for us none of them would be paying for damages caused by our truck, we will be.
Mind you, I actually strongly dislike drums of any kind and size. But I've also been spoiled rotten by air discs, to the point that for every vehicle I get my hands on I eventually start looking for a way to run as many discs as possible. But I don't rush or rig it - our MDT recently got an OEM-disc rear axle of higher GAWR than what the factory gave it at the assembly line, at the same time our 1-ton is still drum-braked due to lack of suitable donor vehicle in existence and will likely stay that way for the rest of its life.
So in the spirit of overkill I'd like to see the OP swap in an entire factory-disc rear axle, that will have everything properly engineered and tested under ridiculous conditions and I personally would feel safe putting my family in such a truck. But if it comes to spending money on drums or so-so discs, it's a judgement call, personally I'll probably choose the drums.