Heh 750F, wish mine ran that cool....
Get a silicone coupler the size of the turbo inlet and connect it to a PVC pipe of appropriate size with a end cap. In the end cap drill/tap/jbweld a compressed air disconnect and then hook that up to your air compressor. Something like one of these guys :
https://www.google.com/search?q=testing+boost+air+compressor&espv=2&biw=2557&bih=1342&source=lnms&tbm=isch&sa=X&ei=HQk4VYvlG6basATamIDwAw&ved=0CAgQ_AUoAw&dpr=1
Then use soapy water to determine where your air leaks are. I have found that they tend to be in the least likely, hardest to get at places. Have you tested your MBC? I had a cheapo one that the ball ended up getting stuck in a place and stayed open the whole time.
Got pics of your IC setup? I am always trying to find a better solution than what I have. Feel free to post it here as well :
http://www.superturbodiesel.com/std/showthread.php?tid=4633