87 blazer 2.8L to 4.3L

I searched but could not find the answer to this question. My friend has a 1987 Chevy S-10 Blazer with a 2.8L. The motor is blown and he's looking to put in a 4.3L without losing the 4X4. Now is this possible and if it is what year of engine does he need and what other components (ECU,TRANS,etc..) Someone mentioned to him that it couldn't be done because of the oil pan? if this is so does someone sell an oilpan to fix this problem. thanx in advance :D

it can be done, but the tranny needs to be replaced also, along with ECM, new wiring harness, have to change the pinouts at the firewall...its a big job.