I need help finding somewhere to find/order a blowoff/bypass valve gasket for my 1989 740 turbo. I had to cut out holes in a incorrect gasket that doesnt fit just so i can create some kind of seal so the boost doesn't fully leak out. However, with the tiny gap in it my turbo will spool up and not send the boost into engine causing it to slowly accelerate and over build boost. Anyone know what gasket this is and where to order it? See pic below:

 

I can't find any such pressure thingie on the parts catalogs for a 1989 740T. the blowoff valve control on both the miitsubishi and garrett turbos is directly connected to the turbo under the intake pipe. there's nothing there above the water pump.

where exactly does the pipe on the bottom of that go? and the larger hose out the side?