I bought the wrong transmission for my 66.

Yes, needs work, 3/4 problem, will need rebuilt, maybe more due to the metal,noise. I'm just not happy with the gear ratios. It was kind of doggish with the 2.92 7 1/4 in 2nd and 3rd, it's better with the 3.55 but now the 3.09 is a bit low. The main problem is this box needs fixed or replaced. I thought I was on the right track when I purchased the A body 833 last weekend. Always a solution right?
Understood. I was asking because I have an extremely low mileage truck A833OD I will not be using.