I too have a 03 classic with a 2.5 200 mercury . Since I have had my boat I have tried everything to get past 67 on gps . I have a 25 tempest plus with 2 plugs out . At 67 I am running 6100 rpms . I have not tried a 26 trophy yet but that is my next try . I put a detwiler jack plate on thinking I could dial it in and that was no help . I run pretty light and most of the time by myself . Most of the time when I post something about my boat the advice I get is that it might just be as good as it will get . I am like you I see everyone talking mid to low 70s and it aint happening for me . Love my boat and everything about it but just want it to be as good as it can be . Hope someone out there can say , oh yeah here is what you need to do . Anyway good luck with yours .