Can this van be modified to hold the weight of 15 mountain bikes and 15 people and climb off road in the mountains?

I live in South America and own a downhill mountiain biking tour company. www.colombianbikejunkies.com
My question is can this 1996 Ford E-350 4.9 Lt V6 climb off road with 3500 lbs on and in it? I have a land rover 110 defender 1994 with a 3.5 Lt V8 that has a mountain biking rack that holds 12 35lb mountain bikes and 10 people. All that weight adds up to about 2300lbs. I climb in the mountain in Colombia to our starting point and then the riders descend back down. I'm wanting to use this ford E-350 van to do the same thing just with more passangers and more bikes with a total weight of around 3500 lbs. I was going to beef up the suspension and add bigger knobbier tires as well for climbing off road. These roads are all rough 2 track dirt and rock. Is this even possible? The problem here is vehicles are twice the price of the US so even this model of van in good shape is 10K USD.
Lastely I have attached a picture of the set I have on the Land Rover to give you an example of what I want to do with this ford van. Any help or alternative ideas would be great! Thanks! This is a link to pics of the van I'm talking about.  

http://articulo.tucarro.com.co/MCO-23411672-ford-econoline-e-350-1996-_JM

This is the 3.5 V8 Land Rover 110 Defender with bike rack for an example of what I want to do to the van.

http://kathiby.picturepush.com/album/243922/p-December-13th-2012-Suarez-Canyon-downhill-through-Barichara-and-Galan.html