I'm thinking the same as mentioned as above - but if you are already at wits end, then I won't say anything more to add to that.
Using the Edelbrock Performer or Performer RPM?
Performer 2176 (or 3776 of with EGR)
Performer RPM 7176
The RPM version sometimes is too tall for a carburetor to fit under the hood.
Personally, I think the Performer is a great intake for a stock or slightly warm 318 - and it does allow for most carburetor usage.
Are you using a Chrysler ignition system?
This can be black, blue or orange.
If not using a Chrysler ignition system, what system are you using?
BudW