I have an '88 gl-10 turbo. 
I am not sure if i need a new turbo or just new gaskets???  I installed a new crossover pipe and reused the old gaskets cause I was lazy and they looked good enough to use.  I took the car for a test drive down the road and got 8 pounds of boost for the first time ever.  As I drove up and down the road, the boost progressively went lower and lower, until it stared to register zero pounds.  I checked and there are no more gaskets there except for the inner rings.  Could the leaks totally eliminate my boost, or could a piece of the gaskets have blown through the turbo and be stuck in there somehow??