Pete,
As for the "L-37", you may be right, I really don't know. I was going by an authentic Chevy list of options produced in '65, broken down by model. For the Chevelle, the list did not show any 396 engines optioned at all, only the Z-16 RPO. Maybe an orignal Z-16 window sticker might show a breakdown of all the equipment and list the L-37
Or maybe it was in some dealer ordering information which explained the option contents.
No offense meant to anyone. I was just trying to be factual.
Verne