HELP!!! Motor swap??

Here's what's up. '87 pick-up 3.0 V-6, 2 wheel drive, 5-spd. Also an '89 pick-up 3.0 V-6, 4 wheel drive, automatic. My question is this, can I put the motor from my 87 into the 89 ? The reason I ask is because, there are 2 different water pumps , one for the 4whl drive, and one for the two whl drive, this difference between the waterpumps , makes me paranoid that the motors may not swap ! I'm in hopes someone out there Knows for sure if these motors will swap !!! Thanks in advance!! cougar