I have an 86 fullsize Blazer with a 305 and a 700r4 tranny. The tranny won't shift out of first gear so I need to do a rebuild on it but I found an ad on Craigslist for a 700r4 from a 4x2 truck for only a couple hundred bucks. If I bought it, would I be able to put it in my Blazer or would I just be throwing money away that I should save for a rebuild? I've been told by some people that it will go in there just fine and others say that I'd have to do some kind of modifying to it. I don't know what the right answer is. I'm a total newb to the transmission game so any help and guidance would be greatly appreciated. Thank you.
The answer is yes. However, the tail shaft needs to be swapped out for the 4wd specific tail shaft. To do so, the entire transmission must be gutted. The tail shaft comes out the front of the transmission.
Unless you pick up a 2WD driveshaft and remove transfer case and front driveshaft so you can run without 4WD until you get yours rebuilt. That's the only way it would be worth it without doing a lot of unecessary work.