EZ, BD step 3's with the HX40 gave me 366 RWHP on the HO. I never dynoed with the EZ alone, but ran that way for a while before the larger turbo and step 3's were added. The EZ alone woke up the sleeping giant and keep the exhaust clear. It's a real kick in the pants for sure. I now run with the EZ and step 5's as a daily driver, keeping the TST for play only, it rocks and has kept me satisfied to date.
For the EZ alone, make sure you install the boost elbow. You will actually see lower egt's than when stock, while making more power. Other than that, maybe a better air filter at the most. Make sure your FP is good as well, I had a bad stumble when I running the EZ alone, turned out to be a dying lift pump.
Scott W.