D13 exhaust leak backside of turbo

Okay, just bought the truck about a month ago. About 1800 miles ago started getting an eek sound only when the ishift transmission would shift. Now its pretty much constant when driving, and engine braking. If I let off accelerator and coast the obnoxious noise stops. Found where it's leaking, appears the two bolts on the backside where it bolts to exhaust manifold are loose. One tightened up, the other just spins. Any ideas? Hoping I can avoid replacing the turbo. Is it too late, you think? I imagine that would explain poor fuel mileage (5.25mpg), and feeling like the truck runs the same loaded or empty?

 

I can get the bolt out. The bolt looks fine. I think whoever had it apart last stripped the hole put over tightening the bolt. If there is 4 bolts there the other 2 must be on the other side. The part am talking about is the bolts that go through manifold to the turbo. To tighten the backside of turbo housing to the flange of the manifold. I got it to quiet down a little tightening the left bolt but the right one, no dice. I'm sure I'll probably have to take the turbo to have it rebuilt by the time I get home Friday. I been getting crap mileage the whole time I've had the truck. I think it probably started off a small exhaust leak, and just got worse. But considering all the issues with the turbo thus far, 5.2mpg doesn't sound too bad. Could be worse I imagine.

 

Would you happen to know where to find specifics as far as horsepower of a turbo HE400VE? I noticed my truck I just bought from this guy nearly two months ago actually has a HE400VG, which from what I can tell is only good for 440 HP, not the 455 the engine is rated for. I am confused as hell about this. Bruckners in Ft. Worth says the turbo that should be on it is HE400VE.