Strange Brake Issue

[Jonlopes]

My truck is having a strange problem with the brakes. The main symptom is I push hard on the pedal and the truck slowly stops. I feel the brakes should have more to them, if I stand on the pedal I cannot make it skid even while unloaded. It does stop but not as good as a Chevelle/ El Camino with 9.5” drums on all 4 wheels. This truck has the huge front discs and equally large 12x2.5 rear drums on the dana 60; though it is heavier it should stop better than an A body with four 9.5" drums? In my experience this would normally be a brake booster issue but the thing is, the feel of the pedal is normal. I have driven cars with bad boosters and the pedal feels hard as a rock and the car is scary slow to stop.
Also there is no pulling to either side while stopping. I already replaced the booster check valve and hose.

My thoughts are:
1. The booster is going bad but not completely there yet. I have never seen this, I have only seen them work or not.
2. This is just how these trucks are, get used to it.
3. Something really weird not allowing either the front or the rear brakes to work.