Where can I get a decent 700r4/4l60 for my 91 blazer. My first one went bad, now the second used one I got won't shift out of first after a couple thousand miles. The local tranny shop wants 1400.oo to rebuild it, I am not even sure wahts wrong with it. Some one said you can get them at autozone for 900 w/warranty? Are the heavy duty ones from the TCI worth it. I kind of want to stay away from getting to pricey to fix it...Any Ideas???