Ah, now I got you. Well I am feeding the right rail, then off the left rail to the regulator (return). The regulator is "regulating" the return side not the feed side. That said, I understand what you are saying and I appreciate the tip.
I am currently contemplating the electronics as I am waiting for some painted brackets to dry. I am also trying to decide if I want to try and drill and tap my water pump as it only has two inlets for temp gauges (the stock electric) and my mechanical gauge. The EFI requires a temp sensor, so I either lose my mechanical gauge or find another way to get into it. I looked at adapters, but they are post thermostat, so I don't think they will work out, or I could replace the water pump.... more $$, or I could just not have a mechanical gauge (not a big fan of that) or I can try and drill and tap my WP housing; if it doesn't work I would have to replace it but that isn't all that big of a deal.
The pictures show where I would have to put it. I think it is possible, but not 100% sure.