[QUOTE=snake428CJwith Flowmater 40's offset...[/QUOTE]
Aren't flowmasters chambered???
The "power drop" you feel is a loss of power below 3,000 or so RPM because the X hasn't been able to start scavenging yet. Your powerband just got moved higher and you won't have that "low end grunt" (not that modulars really have that stock) that you used to have with the stock exhaust.