That looks like a "Mutha Thumpr" garbage grind almost. Those cams are very inefficient. I know its not a CompCam but it looks like it--must have a very late closing exhaust for "that sound". J.Rob
The OP’s cam is a .425” lobe lift solid roller.
The 251/257-106 looks normal enough to me.
(It appears to be a Howard’s 711013-06.
Advertised duration is 283/289. Recommended c/l of 102/110.
That would put the exhaust closing point at 34.5atdc.)
I think this is a situation where two people look at the same thing…….but “see” different things.
RAMM looked at those specs and to him it seemed like a Thumper type grind.
I looked at the specs and to me it’s a normal bracket race type grind.