Chub,,,, The dyna uses a triple turbine system that was the grandaddy to the switch pitch trans..... no, it is not any form of a switch pitch,,, as each turbine comes in and fades out, the next one comes in and finally it goes to 1;1 in high range... Where as the sp th400 actually changes the angle of the vanes in the torque converter.....
1955 was the 1st. year for a switch-pitch converter. It DID have a turbine that changed angles & was known as a "Twin Turbine". The "Triple Turbine" started in '58 & was done by '59 I believe. Tom T.
