Mild LA 318 Cam Recommendations from Those Who Know

Yes, my mistake, badly overcammed. For whatever reason, the 8.3:1 "real world compression ratio" didn't set in. I would go with one of these two grinds in that instance.
Mopar Hydraulic Flat Tappet Camshaft - Beast - Hydraulic Flat Tappet - 273, 340, 360 & 1967-up 318 LA - Mopar/Dodge/Chrysler - Camshafts
Mopar Hydraulic Flat Tappet Camshaft - Beast - Hydraulic Flat Tappet - 273, 340, 360 & 1967-up 318 LA - Mopar/Dodge/Chrysler - Camshafts

As far as the manifold mismatch, I used to prescribe to that school of thought. But after seeing the difference before and after the deep port match in a couple of hydraulic roller cam 318s it actually makes more power all the way from idle on in back to back testing. And that's in heavy 4x4 trucks with big tires and modest gearing. FWIW, there's some magazine small block intake flow testing on line that shows the factory iron 340 intake flows more air than the unmodified performer with 318 port size at the exit flange. But with that bottle neck removed and the performer opened up to a felpro 1213 gasket match, it flows about 20 cfm more. Of course, that gets necked down at the head anyway, but it seems to work better with all the turbulence concentrated right at the pushrod hump instead of it starting several inches ahead of it inside of the manifold flange.