Sorry, I didn't mean it keeps same boost all the way to redline. I just meant it doesn't fall as hard up top. It definitely still falls off but not as bad as a vf40, makes more power, and spools pretty darn close to the vf40 which was the one reason why I went with the vf52. I would consider it a great upgrade to the vf40 for a DD car with still keeping the stock TMIC or LGT TMIC. If you wanted to go with a FMIC or a different top mount I would suggest the hta68. Spools quickly and holds great power up top.
But back to the reason the OP posted. Going with what spc said... I would try and get an idea on how the previous owner ran it. Definitely take it to a subaru garage to get it looked over. Like spc, I am paying for stupid things with my spec b I bought.