I built this several years ago. lots of pics from start to finish. Started out as a $500 project and ended up over $7000 in the end! I will do thes in several posts as there are a lot of pics. 
  
  
The first version made from a plastic JD gator kids toy 
 
 
 
  
Started the new version with a old gocart frame, a crapsman transmission and a briggs 11 hp vertical shaft 
  
 
 
 
  
The ambulance I modeled this after 
  
 
 
 
  
And the plans for the build!