Turbo to manifold bolt size thead grade etc.??

[AL92]

I wrecked one of these some how and I bought better ones it was a new one that wrecked and don't have my old ones.I am having a hard time buying another one.Is it grade 8 or what do they call it in metric. what size what thread what exactly am I lookign for maybe can find one local.My local dealer wants like 18 dollars for one bolt.!!
and might have to fix the current threads what tap would I use..
If the above stock route fails then likely drill and tap for 7/16 and be done with that.
Also anyone drill thru the housing and put a nut on the other side.my threads still look ok most of the way down but near the top they are fubar.
Also is there supposed to be a light raised ring around the bolt hole on the turbo exhaust housing.Or did I do that from the bolt being messed up and cross threaded or something??

 

[pimpngear]

Both slowboy and mach V have bolts and washers for a decent price, I think around 30 with shipping. I feel your paine. I breake these things more than any other single part. Good luck.
-Rob