When I read your answer/question more carefully I think the 1406 would work perfect on your 318, but where in the chart you would end up depends on many factors, the deleted EGR might change versus if you did'nt delete it, but it must be tuned by running it to see where in the chart you should be going, the best thing is to start with 1406 standard tuning and go from there.
Standard 1406 would give you 0.0023 opening in the jet for cruise and 0.0051 power opening (main jet minus rod thickness in inches)
#19 would give you 0.0028 opening in the jet for cruise and 0.0061 power opening
#23 would give you 0.0025 opening in the jet for cruise and 0.0056 power opening
Standard 1405 would give you 0.0030 opening in the jet for cruise and 0.0053 power opening, wich is 0.0007 richer in cruise and 0.0002 richer in power compared with standar 1406 setup.
On my 383 0.0028 gives me an AFR about 14-15 at highway cruise wich I'm pleased with, but 0.0053 is a bit rich in powermode for my 383, that gives me an AFR about 11.
At 0.0040 or 0.0045 in power mode gives me an AFR about 12-13 and works better on my engine, so I'm way out of the shaded area.
Good luck and I hope you dont get the famous bog but I thing the 1406 air valve works better on a smaller engine.
