I don't have pics of the back of the housing... i do remember it was a decent sized hole cut out of the housing... i talked with raceoholic and mustang5l5 when i did mine... look up raceoholic's thread, really good info.
It's on both sites. Here's the stangnet thread. The thread on the corral has other people chiming in with their setups as well. One guy made his own custom shrouds on a CNC machine. They were really nice.