318 LA torque?
A stock two barrel 1968 318 puts out 340 ft/lbs, the same as the 340 just at a lower rpm.
That's what the advertising says yes.
But ask yourself how this is possible. This goes back to effective pressure.
To the 340 cam above, I arbitrarily added 16* to both ends of the 268, to get that 300* seat to seat,not-leaking, and a realistic 9.9 Scr to get a predicted pressure of 133psi@ sealevel.
I wouldn't think the 318 cam would have quite as slow ramps, so still guessing, lets give it 12* at each end, added to the factory 240/248/112 cam that would make it 264/272/112 seat-to seat closed and not leaking. In at 108 the Ica would be 60 and at a realistic 7.8Scr the pressure would be predicted to be 123psi ...
So now, there is only 10 psi pressure difference between them.
And so after cylinder filling efficiencies are worked out, say the 318 hits 5% better at 2400, than the 340, it's easy to see the 318 being nearly as peppy to more peppy, than the 340, in the lower rpms,all other things being equal.
And that's why I would never recommend to put a 340 cam into an X-headed smogger-teen city-car, with a 1750stall TC and 3.23s,lol. That was not one of my better ideas; but a 2800 and 4.10s sorta took the sting away.That was a one-time lesson, over 40 years ago.
