Need Help installing AEM FPR

[tboogs12]

I am pretty well versed but I am not done learning. I am working on my build and I decided to add an AEM FPR just to be on the safe side. I have a Walbro in the tank but I just dont wanna take the chance of running too lean or too rich. My issue is that I am running it in line with the stock FPR. So do install it before or after and also I can not remember for the life of me which is the feed and return line. Yeah its been apart for a while and the labels fell off. So if anyone has a diagram of the fuel system that would be great as well. Thanks guys.