I agree with therealnighthogs statement as well. But most people dont like to have to drill and tap things, so they take the (easy way out). I personallt think its easiest to pull the 2 throttle body coolant lines off the coolant piece behind the block and just run hose from there to the turbo.
Drilling and tapping doesnt bother me, i have to do it often at work. But, i wasnt using the tb coolant lines anyway.