I had my saddles plumbed parallel and those fed the main bottom tank which is shaped in a way you will get full clunk travel. While inverted, if the saddle tanks sucked air, your main tank will feed properly. When right side up, the saddles will continue to draw fuel normally. In my A-4 I was able to use all the fuel reliably with no issues. I sold the A-4 with over 100 perfect flights on it. Good Luck!