340 cam specs?

I actually question if that Erson cam is still in my car. One of the previous owners that I spoke to had the motor built with that cam. He said the car never loped like it does now. The only changes made after him were the mufflers I believe. I’m still trying to piece everything together as far as the car is concerned and what I have. I thought I had 3.91 gears but I actually have 3.23’s.