I would try shifting it out of low at 7000 PM and see what that does to all the times on slips, 60 Ft.' 330 and 660 ET and MPH.
If that slows your car down try shifting it sooner, say at 6200 or 6300 RPM out of low gear scope twocents up

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)