Ok I just replaced the motor in my late 99 power stroke. Unfortunatley blowing my motor helped me find my Boost problem. The EBP line from the passenger side manifold to the EBP sensor above the water pump had a 1" piece rusted out which was leaking EXH. out of it and dropping my boost. The area is rusted out was behing the A/C comp. Bracket where you cant see it. The motor I put in was out of a 2000 and that same line is stainless so Im assuming after 99 the fixed that problem. I hope this helps all you guys having boost problems. Let me know who else finds this problem.