i been looking crazy for a Saginaw SM465 four-speed manual to put in my 1991 k5 blazer instead of the automatic i cant find anyone who has one so is there any new transmissions that would work? im having trouble finding them

 

They are all over the place around me. The '74 Jimmy I am going to be picking up shortly has one in it.

The problems you will run into are going to be with your driveshafts and transfer case. You will have to get the whole setup from clutch linkage to driveshafts.