Speedway torque converters

I was at the old school mini bike show in Royal Oak, MI this past spring and someone told me the name of the company that made the torque converters for Speedway models like the Shrike and Scorpion. I know it was not Comet but does anyone know the other company? I think it started with an "E" but I could be wrong. I know int he brochures Speedway called them the "Dyna Torque 400" but I don't think that was a trade name. Would love some info on this for my Shrike restore.
Speedway used an in house torque converter drive and driven in 70 and 71 in early 72 they had the same drive but switched to the Fairbanks driven they also used a comet driver in late 72-73 with the Fairbanks driven. Very late 73 they switched to salsbury drivens and drivers. When they switched to the Salisbury’s they also had the cutout modified so it would fit.