The big issue with old steel lines is rust. I've had fuel lines on 60/62s crumble as I was taking them off the frames. Same applies to brake lines, pulled off my share of rusted through as well.
It is a philosophy with me I guess. I feel that if you are spending the money and time to put EFI on a 30-40 year old truck that you should replace the fuel system along with it. Clean your tank while you are at it as well. To be honest, I find it somewhat amusing that some folks would rather spend hundreds of dollars on what amounts to a mini fuel tank and pump simply to avoid doing the job right. What they are left with is an old fuel system feeding a new fuel system that feeds a new fuel injection system, crazy IMHO. Not to mention they now have two fuel systems to keep up with.
This is a Tanks Inc pump set up for vehicles that do not already have a baffled pickup in the tank. It can be installed in an afternoon.
If you are a tool guy this also gives you opportunity to buy a cool tool if you do not already have one. You can make fuel lines in AN with the extra die. You can also make brake lines, power steering lines, auto trans lines with this tool