have a read of this, looks like a common swap in early CJs if you have the SR4 gearbox using a combination of off the shelf parts
blazers probably got a t5 with a 231 transfer casehttp://www.ebay.co.uk/itm/Chevy-S10-Blazer-Spares-Repair-/270923705940?pt=Automobiles_UK&hash=item3f144fae54