Still sounds like a converter issue to me. If the car is not spinning the 60 foot is a little lazy even for the MPH that you are running right now. WIth the glide my guess would be your shift recovery is pretty slow, Would be interesting to see a time slip to see how strong the car is pulling from 1000 to 1320 feet to get an idea of how much power the car is actually making. With out more data pretty tought to diagnose further but the combination (independant of the dyno numbers) under your conditions should see another 10 MPH and run closer to 8.90s (if the chassis is sorted out as well). Similiar to others experiences with my old car just a converter and some chassis tweaking netted a 5 tenths improvement. That was with a lower powered wedge combo going from 10.3 to 9.8 MPH increaseds 7 MPH. Went from an 8 inch converter to 9 inch and never looked back.