1990 Mazda MPV 4WD? Can it be done cheap?

I just purchased a 1990 Mazda MPV minivan. It has a stock 4WD system with a locking front\rear diff. It doesn't have 4 low. I want to make it a mild to moderate trail rig for camping, but still be efficient to use as a daily driver. I drive the van every day and haul equipment for my DJ company. So, my friends in the off road  community, my question to you is this; Can it be done?  We shall see... Any suggestions?....  

My comment to you is "anything can be done if you have the money." The big problem is the engine in is the transverse position (meaning the cylinders are left to right as opposed to front to back) This mates to a "trans axle" (the axle is directly connected to the transmission) I am not sure how the 4WD/AWD works on transverse engines, but I am sure there is a third drive section in the trans axle that connects to a rear drive shaft.

The locking is most likely a part of the 4WD/AWD system and not in the axles, But I know I could be wrong. This type of locking system is seen in the NP203 from what I have found. This allows the power to go to both front and rear axles to get the best traction. Additionally, when the vehicle has ABS, in some vehicles (at least newer ones that I know) the ABS is a part of the traction control system. When the computer senses slipping, it engages the brakes to the slipping wheels so the power can go to the wheel(s) that have the traction.

Best bet would to go with an Astro/Safari vans. They have a traditional engine position and had an AWD option. This would be easier to upgrade in the manner that you are looking to do (in my opinion)  
'91 K1500 (Stock)
LT285/75R16
Play hard! Play soft! As long as you are having fun!

You pointed out some problems that I hadn't even thought of. Thanks for the input. I used to have an all wheel drive Astro, and I wish I knew then what I know now... I am still gonna look into maybe just putting more aggressive tread on it, and maybe a small lift (maybe). Again, thanks.  

1st of all that year MPV is RWD !!!!!  so the engine is in a north south position !!  I think it may be the Navajo system under it which would mean if you can that will be your best thing to look at for a donor