High Altitude Camshaft Selection

That's awesome, the more I look into overdrive options the more I like an add-on unit like the GV. I would love to swap in a modern Tremec but that would be a "never look back" kind of deal; I like the thought of keeping my current trans and being able to swap the unit if/when I decide to put in a 4-speed, or even if I do someday put in a modern OD trans I can probably sell the GV unit for a good price as I can't find used ones for sale anywhere lol!