Is the clutch why you don't want to drive it far?
And yes, no one read the part that says "The M21 in the car is
not the original trans so I don't really care that much about it."
Classic Chevy 5 Speed all the way if you are buying it new. I spent an hour talking transmission issues with Jeff - I do not have any of his products, BTW. But you probably know that from Team Camaro.