Just finnished installing the 500 in my 4x4 truck.The fuel pump has two ports coming from it.Since i do not have a return lines to my dual tanks,can I block the other outlet off or would there be problems?

You can block the return off. It's there to lower fuel temperature at the carbonator inlet. If you have problems with hot restarts then consider plumbing a return line to the tank.

Thanks Ape Man ,I just blocked it off and it seems to work fine so far.A real problem that I have is that I run each tank seperately so having a return line would be a PITA.