LS1 fuel system set up

HI:

I'm installing a '99 LS! in an old 'ride and am wondering about how to set up the fuel system. It turns out my engine has the return line plumbed in with a factory regulator. I have a MSD #2225 fuel pump, as well as a mallory adjustable fuel pressure regulator.

- do I need the mallory regulator if I have the factory on on the engine?

- what types of connectors do I need for connecting the lines, etc?

- what else do I need?

any info, hints or past experiences would be most helpful.

Thanks,

-BV