L59 Flex Fuel 5.3 engine question

[Mattt]

I have a question on the L59 5.3 flex fuel engine fuel/intake system.   Up thru 2004 the L59 has a return fuel line that returns to the fuel tank.   The 2005-06 has no return line back to the fuel tank but instead has a different fuel pump that apparently regulates fuel to the rail.    I have a 2004 truck equipped with the L59 engine (with return line).  

 

Is it possible to swap the fuel pump to the later style, abandon the fuel return line, and run the 04 like an 05-06 L59 5.3?   The reason I ask about doing this is I want to swap to the 2007+ NNBS or TBSS intake manifold and that system also has no fuel return line either.

 

I have found most people use a particular Corvette fuel filter with the built in pressure regulator and fuel return line fitting when swapping to the newer intake manifold on an older GMT800 truck.  I was looking at this option as an alternative.

 

How much of a difference in how the fuel system/intake/fuel pump module work on an L59 from is there between this cross over when GM did away with the fuel return line to the fuel tank? Is the only difference the fuel pump?   Is the flex fuel sensor the same or different? 

Thank you very much in advance for any and all insight.