nice find John.
Here's my thought on this car. Looks like a 68 LO23 due to the round side markers & the rear wheel well mods that ran Super Stock. It was then converted to a 69 either by direction from Ma Mopar because it was with a factory backed team, or was coverted to be current as a Pro Stock in 1970? Then it started it's hand me down status into classes such as this. Of course this is pure speculation.
It has the base colors of the old Joe Teuton Southland flyer Dart
liteweight
input?