We all agree that the stock transmission brake isn't particularly effective, but I realized something clever about it. In the days of bad roads, fording rivers, etc., wheel brakes were prone to getting junk in them, preventing them from working properly.
However, since the transmission brake is enclosed, the brake will always work regardless of what happens to the wheel brakes!
Until you have a problem with the driveline, like a spilt pinion gear. Then you have nothing.
There were different types braking systems employed. One type the brake was in the differential. Wheel brakes also suffer when oil from the rear end leaks on them.
I'd have to say the Improved Ford's transmission brake is very effective. I haven't driven many pre 26's, but from what I've experienced, the wider brake drum/band makes a big difference.
Even so, I prefer to use the rear drum brakes most of the time to save drive train stresses and band wear.
You can buy the equalizer kit from Lang's which makes your '26-27 drum brakes the main braking agent connected to the brake pedal- try that idea as well.
The is a very funny Video of a Model T with one back wheel spinning in reverse and the other running forward.
Well it was funny to watch, scary as s**t to the driver... That's why I like my Rocky Mountain Brakes