You want to see street HP, plug some numbers into this calculator, and watch the P/V numbers which are an indicator of low-rpm torque, to somewhere around 3000>3500rpm, which is the rpm of interest for most streeters. Unless by some crazy miracle they buy a higher than factory-stall converter, which never seems to be in the budget..... like compression...........
Everybody wants to bolt on this and that and install a big cam, and suddenly Shazzam you got what HP? well maybe you get a few hp, but at 5000rpm which with the typical 2.76s , doesn't come around until 56mph in first gear. Meanwhile the lazy sob can't even chirp the tires., cuz the bottom end is gone. That's not performance.
And notta chance do you need bigport heads/4bbl intake/and a windage-tray on a stock-cam, lo-compression, single-exhaust 318 turdmobile, with factory stalls and hiway gears; and especially not with that 114LSA/340 cam, which is gunna drop your CCP some 18%psi, Maaaaybe you can pull a few horsepower out of it at 4800rpm, if the rods keep getting oil....but the entire bottom end all the way to ~3600 is gunna be softer than my wife's bellyfat, Bin there done that, more than once, and will never do it again.
You want a hi-perf 318?
Job one is get the stinking pressure up. Way up, like 195psi/now yur talking! Course you can't get that with any stock head, and maybe not with aftermarkets, and you can't run iron heads at that pressure either, but go ahead and bolt some alloys on there, and then put the 2bbl back on with the factory cam, Shazzam yur gunna have tire frying torque, right off idle.
Second best and with iron heads would be 165psi with a tight quench.
Here's the deal, with a torqueflite, on the 1-2 shift, the Rs fall to 59%. If yur teener doesn't have torque at 59% of whatever you shifted at, your performance just came to a screeching halt. With a factory cam, peaking around 4400, you might carry that to 4800, and 59% of that is ~2800. Un-hunh. 2800.
But with the 340 cam making 115psi, what are you gunna expect with those 2.73 gears turning 56mph. Yur done, and have been done since 50mph. That ain't performance. And the hi-stall , say a 2800, isn't gunna help you one tiny bit on that rpm drop....... And rear gears, only bring this problem down to a lower roadspeed. The problem, with the 340 cam ina sub 8/1 318, is a total lack of cylinder pressure.
I would put that $140 towards pistons, no question.
But-um hey
Theses are my opinions.
And
If yur not gunna up the pressure, just get a bigger engine that already has inherently more torque. Something with a longer stroke sounds about right.