my Low dollar 318 hop-up project

This really is a interesting thread. Doing more with less, gotta love it.
One thing that I seen is the spring pulling your kickdown lever should go from the cable stud back to the bellcrank arm by the firewall. There is a little hole in it for the spring. Of course linkages are different through the years, so I might be all wet.
As it is now you might not get full throttle opening on the carb.
From what I read, 70 340 Dusters with a 3:55 gear ran 14:70's. You're right there with a carb tune.
To bad your not closer, I'd let you use my 650 Eddie carb.