??? Unless I'm missing something, a 3.09 low gear would need to mesh with a counter shaft for a 3.09 low gear. A 2.66 counter shaft wouldn't work. So unless the other three gears were the exact same ratios, the other gears from a 2.66 trans likewise wouldn't mesh with a counter shaft for the 3.09 low gear trans. At any rate, my memory is that the entire gear set and countershaft in my later trans case are from my original 65 Barracuda trans.