Fuel line help!

I just put a 190 lph fuel pump in to support my 30 lbs. injectors. I know I need to run new fuel lines from the tank to the engine bay. Anyone know the length of the line needed to do this? My dad was suggesting that we use the old delivery line as the new return line, would this work out alright? Any suggestions or pictures would be most appreciated!
 
Maybe I should have stated better what I have: 347 stroker, I already have the 30 lbs. injectors and fuel pump installed. I have a Mallory fuel rail set up with an adjustable fuel pressure regulator. The rail instructions highly recommend upgrading the fuel lines to support the higher flow of the 190 lph fuel pump to the rails.
 
Thank you S/CBlack95GT. Have you ever had any fuel starvation problems at all? The reason I want to be absolutely sure about this is because I have to drive this car with the brand new (haven't even started it yet) 347 in it about 1500 miles from Seattle to Tempe in about a week. I'll be starting school again and will have no access to any real tools or a garage (I hate dorms). I have to make certain the fuel lines.. and everything else.. is perfect. Thanks guys.
 
My car had more than enough fuel. It actually had enough fuel to totally drop the A/F ratio off the rich side of the graph, which is a 10:1. Right now I have the initial pressure at 42psi along with a small 4:1 FMU. Even with that the car runs no leaner than an 11:1 over 4500rpms.