By booster, you mean the vacuum booster...not the brake controller right? I doubt it's the vacuum booster. But ultimately nothing can be ruled out. It could be someone replaced the M/C at one time and put the incorrect one on, or didn't adjust the rod properly.
I'll toss a few more ideas out, though you probably looked into some of these:
1) Caliper/brake pad sliding surfaces: When you replaced the rotors and calipers just curious if you inspected the sliding portion of the knuckles? As miles accumulate, some can develop a 'groove' where the brake pad normally sits. Like
THIS. And the metal tab on the brake pads can get 'stuck' in that groove. A lot of brake shops overlook this. Some have welded in and ground back down.
2) Stainless Steel pad adapters. If your truck has these between the brake pad and the knuckle, ensure there isnt' any rust, dirt or debris, beneath them (which often occurs). This condition can keep brake pads from smoothly and easily retracting back from the rotors after each braking process. Or put differently, a brake pad can stay stuck against a rotor after braking and build up heat.
3) Calipers: Ensure they are smoothly retracting back. Just because they are 'rebuilt' doesn't mean an o-ring didn't inadvertantly get twisted and causing the piston to hang up. Check each wheel (vehicle jacked up) that it rotates freely after pedal release.
4) Master Cylinder Rod not adjusted properly: If the master cylinder had been replaced at some point, it's possible the rod length is incorrect for some reason ...and the master cylinder piston isn't fully allowed to retract.
5) ABS? IDK if there are ABS module (and sticking valve) issues on 3rd gen's. Here's where I'm out of my element on 3rd gen specifics. Others might be able to help here.
6) A weak or collapses brake hose: can do what you described. But you say you replaced the hoses. So Hmmm... so probably not this.
You probably checked some of the things above. The best would be if you can isolate it to a particular wheel/wheels. Use a IR temp gun on the rotors to see which wheels are heating up most/fastest, and start by attacking those. Or are you seeing all of them heating up?
