Why do you think you need a “Monster” transmission? Unless you are over 400 hp, is kind of a waste of money. You can rebuild the one you have for less money and probably end up with a more reliable setup.
If you are going to crank some big horsepower, than by all means consider the 4L80e. It is relatively easy to install. It bolts right up, but some parts need to be changed out to complete the swap. I smoked a couple of 4l60. monster tranny’s and the 4L80e was the only solution for my application.
You probably don’t need the Monster and your local tranny shop can do the upgrades to your transmission that make sense for less money. Also keep in mine, programming is part of the secret to making the trans last and perform properly……. Just my .02
I would also resist taking out a loan for a repair. Try to wait till you have the cash…….
I assume you can remove and replace it yourself to save money………