You should have been in a completely different gear with that big of a change. I.e. with 4.56 I was trapping at 5,200 in OD (GVOD) and with 4.10 I trap at 6,200 in 3rd gear with a 727.
I'm unsure what you think a significant gain is, but if you went from 4.10 to 3.55 with no change in trap gear, trap RPM or 60 ft time it is a little beyond my understanding.