Update:
I drove the truck for a couple of hours today and hauled some wood. I don't really feel like I'm even using the brakes anymore. I can't describe it. I touch the pedal and the truck just slows right down, like it has velvet brakes powered by some sort of galactic fuel cell. It's like magic, and eerily smooth. I find myself trying the brakes randomly, just to feel the lack of anything resembling "normal brakes"....if that makes any sense.
Overall, I have to say I am more than satisfied with the results. I did remove the proportioning valve at the same time as this mod, but it only makes it sweeter. There was no fade at all today, and I had more confidence going down hills and into turns. The brakes felt the same every time I used them, smooth and strong.
I have driven trucks with 4 disk brakes, and was not happy with the feel. They always felt grabby, like the truck wanted to slow down faster than I wanted it to. These drilled drums feel much better than disks and are easier to control. They are not grabby at all, and respond exactly to pedal input. I had heard this from others who drilled their drums, but never expected it to be so literal. They really are better than disk brakes, and there is no chance of stuck/rusted guide pins, warped rotors, frozen calipers, or pads wearing unevenly. I have had to fix more disk brakes than I can count. Drums? Ummmm, let me see....less than 5.
This is a big thing for me. A total game changer. If people could try drilled drums, I really think they would leave disks in the dust...haha, dust.
I really like having some extra brake power in the rear now. The truck doesn't feel nose heavy and stays level when stopping. The proportioning valve was cutting rear pressure at only 200 psi, meaning there was only 125 psi of braking pressure left after opening the shoes, since it takes ~75 psi to overcome the return spring tension. Now I can have as much pressure as I need, 400 psi, 800 psi, or even 1200 psi, if needed.
The big double piston calipers up front help balance the braking force, but I think the drums have the advantage, since they require less line pressure to achieve the same stopping force. The only reason the fronts work as well as the rear is because of the double pistons multiplying the pressure. Single piston calipers would never have a chance at balancing with the drums.
I am giving this project a score of 20 out of 10, because it is WAY better than I ever expected it to be. I am tempted to put drums on the front too.
If anyone is on the fence with drilled drums, I say go for it. As long as you use your brain when drilling, you will be just fine. Every part of the shoes must be swept by a hole or you get streaking, uneven wear, and hot spots. Keep things balanced. Need I say more?
Disclaimer: I removed my proportioning valve along with drilling the drums. It is not neccesary to do this. Messing with the proportioning valve may be dangerous and should only be done by those with the proper know-how. I take no responsibily for the outcome of actions performed by those who read this. Be safe. I think that is all I need to say about that.
That is the end of this review. If you have any questions, feel free to ask. I am more than happy to answer them. If you are not comfortable drilling your drums, but would like them drilled, let me know, I may be able to help.