Suggestions for muscle car sound muffler without drone

I'm trying to get rid of drone at about 107 Hz. After doing the calculations its just over 31 inches, which might just barely fit in the back after the mufflers, however it would fit much better along the straight pipes after the downtubes. Do you think that my calculations will be off since the resonators will be placed before the mufflers? It seems like they would change the pitch of the drone that I am trying to eliminate.