Cam Swap - 318/5.2L Magnum V8 - '65 Barracuda

The cam specs in post#2 are little different from a factory 340 cam. They just tightened up the LDA and added a bit of lift. Now if they increased the rate of lift, to put more area under the curve, that would explain the springing requirement. That would tighten up the powerband and increase the specific power slightly from the factory 340 cam.So it would, seat-of-the-pants, sound and feel faster. But the early ICA tells the real story.Premium gas, and burning more of it, and I suspect, very little change in ET or MPH.Especially with an automatic, and non-optimum rear gears. But if it's the idle you're after, and are able to tune a timing curve,and don't mind the high cost per mile of gas, there you go.
To me, it's like those guys with fart can mufflers.
I had one cam with a 108LDA. Performance-wise,on the street; it sucked.And that was with everything optimized. I won't be buying another any time soon.
On the street,in a car that gets driven,it's hard to beat a wide powerband, that starts real low, can use a tight TC,and 3.23s or 3.55s, even if that means a sacrifice in specific power. It's nice to have a gear that goes to 50 mph or so,before having to shift. That means 3.55s with a tall tire.It's even nicer to have a combo that puts second gear at or near peak torque when the TC flashes, and at cruising speed.But once again, I digress.Sorry.