SS/K 1965 Valiant

That makes more sense = 131.76 in the 11's did not
to me particularly for a Superstocker.

Thanks for clarifying that, now that makes perfect sense to me!

The stick Superstock cars often run a bit more MPH for their ET.
Even with the state of the arts clutch technology (Slider set up) many
if not most Stick Superstocker run bias ply slicks rather than the radial
ply slicks you see on most auto Superstockers. This is especially true if
you are not running Heads Up in a class runoff as the radials are not forgiving
of a marginal track surface.
Our SS/KA Superstock will run .12 to .14 slower with the bias tires although without
much or any MPH difference.

I suspect because of the greater growth rate of the bias particular in High Gear.
At least that is my guess.