1968 340 Cam Choice (Again)

I offer to put a stock 318 cam in it, you'll have so much scary torque you'll flip your lid. And finally get some pressure into those aluminum heads, which they are begging for. Yeah the power will peak early but with those Eddie springs you'll be able to shift it at whatever.
With a 4-speed and 3.23s, 60mph in second will be about 4650rpm , so that's thru the power peak twice and change. That will add up to a good amount of average power.
And you probably have a 318 cam just laying around. For a bit-O-fun slap in a set of solid lifters and an adjustable valve gear. Oh sorry, you said no solids,lol.

30 mph in 2.66 first will be about 3320 rpm, very close to peak torque with that little cam,maybe a lil after, so at 3200#s,and 235 tires, there will be tirespin, so hang on.
But sorry, no rumpiddy rump.
Instead, with a lil effort, you might get her to idle down to 450 rpm at 4.0 mph, so maybe you can parade her. Won't be able to with the 340 cam, except by slipping the clutch, cuz even if you get her down to 650 idle, this will still be 5.8 mph, and she'll probably get jumpy on you unless you retard the timing.

Iron manifolds will kill the overlap anyway so any 340-type cam you stick in her is not gonna give you the top-end rush you might hope for.And a slow-ramp cam is just gonna kill off some pressure... which kills torque, and by definition, power; so why bother with the aluminum heads. So while the power will be there with a bigger cam, it's kindof moot cuz all yur gonna get out of it from zero to 60 mph, is extra tirespin.
Just my opinion.

But if you also crave a low ET with 3.23s, well the 318 cam is not the one, cuz your trap speed is gonna be into the low 5000s in third gear, so you will need a cam closer to the 340 one, just with faster ramps; waaay faster ramps, to keep the pressure up.