FWIW there is a performance blog about one of the T-Bird Super Coupes that a fellah was 'tweaking' that he included the testing he did before and after each mod (along with dyno time IIRC).
Can't seem to find it now, but it goes along with what jlgrooms said, he actually lost a small amount of 'boost' when he got a free-er flowing exhaust on his car, but picked up some HP and Torque as well as lowering the EGT (in the beginning he measured the exhaust pressure to be higher than the boost pressure
).
That was before he put the smaller blower pulley on IIRC (wish I could find it, it was very informative).
Pertinent because it had the M-92 on it as well (somewhat different 'plumbing' though
).
