mine is a similar spec to yours... is the t38 a turbo technics one as some of these had problems with the wastegate arm bending which mine did and didnt make any boost under 5k.. had the inconel arm fitted and and i cant tell much difference in lag from my old t34..
when i took the turbo off you couldnt see that it didnt seal properly but i put a thin layer of white paint round the penny and closed it tight and only half the circle touched on the housing.... turned around in under a week and well happy now..