The issue with running a t is that the fuel will take the easiest path possible, which is the unblocked line back into the tank. If you make the return line small enough and put a pressure regulator on the line to your carb it might work, but you risk your carb running lean.
I am running a low pressure in-line pump and a fuel pressure regulator, both designed for an old carbureted v8, at 3.5 lbs. The only time I run into an issue is if I let it sit in one place idling for 5 minutes or so, the fuel pump starts to make some noise as if it is cavitating. Probably because I don't have enough fuel going through it to keep it cool. But it has never been an issue and has worked fine since installation.
If your running the stock fuel pump it already has fuel bypass built in, just toss on a pressure regulator on there from your local autozone and call it good.