650 cfm carb is fine even for a stock 318, cam I'd go with a comp xe250 biggest I'd go is the xe262. They do xe256 if you want split the difference or cams of similar specs.
Thanks, That's a great article for any Teen owner that want's a little more. I bet just a little head work and 300 horse would be on the dyno screen. That would be fun in any A Body.