73 blazer tranny swap??

I have a 73 blazer and it wont shift from first i got another tranny and was told its a turbo 400 i was wondering if this is interchangeable into my rig, the pan on tranny in my truck has a slanted corner and the one i got recently is totally square. also the tranny im thinking about putting in has electrical plugs on it and i dont know what they are for hopefully just speedo and trouble lights that i dont need, but im not sure, i also dont know if it was going to mount to my transfer case I ink it came out of a 2 wheel drive

so is this a bad idea all together or will it bolt right up  

well that tranny is definatly not a turbo 400 i tink it is a 700r4. And with all the electrical conections you are talking about you may not be able to use it, especially if it is from a 2wd. If it is from a 2wd you could get a divorced transfercase.  
'80 chev stepside,3/4 ton, 4 spd, 40" interco's, crazy flex, and one good driver lol

so what transmission is in my truck is it the 350?  

It is a THM 350 and it was bolted to a NP203 Tcase from factory too. If you still have 203, now would be a good time to upgrade. You could swap a 700R4 and NP208 fairly easily as they were installed in later models in mid 80's.  

how strong are 208 tranfercases? would they be suitable for hard croe wheelin? and what is the low range gear?  
'80 chev stepside,3/4 ton, 4 spd, 40" interco's, crazy flex, and one good driver lol

A 208 is a pretty simple and sturdy box and as long as you are not trying to run 35's with 3.42 gears or so it will hold up just fine. What is hard on Tcases is people that install big tires and do not regear axles. (it strains tranny and Tcase) Low range is about 2.6 to one on 208 vs 2 to 1 on 205 and 203.