What he said. The mph didn't change much, pointing to other factors. Water grains seem to have a bigger effect on my car rather than just outright temps. FWIW, 104 doesn't do much. For some actual octane boost, Lucas, NOS, Torco and a few others will work. But they all contain MMT, which will turn your plugs orange pretty quick. If you don't need the octane, don't run it. Octane is resistance to burning.
'84 LTD LX - 9.83 at 140.09. Whippled 365 SBF with a glide and 3.08 gears. Driven to and from the track 60 miles without even changing tire pressure.