318 cam

Not only the cam but the entire 318-top end, did I install. That was about 1974, and those were the parts that I had.
Plenty of cylinder pressure, and low-rpm TORQUE was the result. Which for me, made more than adequate street performance for the lightweight-A that I put it into.

The 340 cam installed at 110, has in Ica of 64*. In a 10/1 340, this will make about 163 psi and a modest V/P of 129 .

The 318 cam installed at 108 has an Ica of 48*. In a 10/1 340, this will make about 187psi and a super strong V/P of 166

That big V/P will let you run a factory stall, which is usually 1800/2000, which will stall a lil higher at the higher V/P; and very small rear gears, down to 2.76s.
whereas that V/P of 129 wants a stall in the mid to high 2000s, and at least 3.23 gears.

The small-port head 340 with the 318 cam, will power-peak at ~4200, and will want to be shifted at ~ 4600 rpm, With 2.76 gears, this will be close to 55(zero-slip) mph in First gear.
The big-port 340 with the 268 cam , will easily go to 5000, and will want to be shifted around 5500. With 3.23s this comes to ~56 mph(zero-slip) in first gear.
The difference of course is that the bigport headed 340 will make more absolute power.
The question is, which will get to 55 the quickest on street-tires, and on the street..., cuz that 318 cammed 340 is gonna spin right alongside the 340 cammed 340. If she gets ahead off the line, there's no telling which will ET lower.
In the meantime;
if you have never driven a modest-stall car with a V/P of 166;
I can tell you that a 68 Magnum 440, makes a V/P of ~167.........
And the good news is, the very high cylinder pressure is insanely responsive to the throttle, and/or you can gear it to idle down the hiway and get EFI-type mpgs.
And the bad news is, that the gasolines of today, no longer have the octane to support 187 psi with iron heads at full power.

so then, you gotta consider the alternatives;
Like alloy heads, or injection of an anti-detonant.
I wouldn't do this today, because;
1) I just ain't that poor,
2) I can't buy gas for it
3) that was a moment in history; I turned 21 that summer.

Today, at age 70, I am contemplating installing a 10/1 360 with a 360 2bbl cam, into something around 3400 pounds. The pressure may be too high for even 91 gas, but I got some ideas... I'm expecting point to point fuel-economy in the high 20's/low 30's, in overdrive.
BTW
I ran headers on that combo, as I do on almost all my combos.
Neither the 318 cam nor the 360 actually "need" headers because neither of them have much overlap. But in my experience, a 318 4bbl really wakes up with headers. The inertial tuning still works, helping to evacuate the cylinders on the exhaust stroke, which, if the rings are working, will, with the smallport topend, will yank pretty hard on the plenum.


Read about V/P here; V/P Index Calculation