Trans brake, internal or external, solenoid?

[Tom Goldman]

Having used both the ATI internal Powerglide brake and the Griner internal TH400 brake ,I can tell you the ATI will change about .015 after about 3 hot laps.
The Griner on the other hand did not vary on bit hot lapping, probably due to the physical size of the solenoid valve and the passages.
The ATI unit is obsolete, I sold about a dozen take outs to mud racers , perfect for them !