[camcojb]

That way definitely works, but you may end up needing a fuel cooler on the return line if you do a lot of driving. Doesn't occur on all cars, but I've seen enough cars stuck on the side of the road on Power Tour to know it can be an issue.

The reason you see most LS swaps with a single fuel line is because that's the way the factory did it on the later model Vettes, etc. The fuel filter contained the regulator and bypass line back to the tank. The factory computer used PWM to control the pump, and the results were a simple install that works great. With the fuel not being heated by the fuel rails and engine compartment and then being returned to the tank, plus the computer controlling the pump output you eliminated the heat issues. There are guys running similar setup to way past your HP without issues. Also saves money on the return line to the tank since it returns near the rear of the car off the inline filter. Fuel doesn't get heated by the fuel rails to be returned to the tank, bypasses that entire deal.

The absolute best fuel system in my opinion is a Vaporworx system from Carl Casanova, installed in a quality tank like Rick's or DSE. That system picks up every last gallon of fuel in the tank without slosh issues, has a controller for the pump, and can support a LOT of power. This one doesn't even need the bypassing filter outside the tank, does it all internally. Plus again only one line to the engine.