vacuum reference port

You lost me here..........You are NOT boosted, right? If not you do NOT want pressure compensation

So far as a return, don't make the mistake I did.....you want the return at least as large as the supply. This is because the return is at lower pressure than the supply, and needs to be larger to flow volume
nope, i am not boosted (i wish i was)

i just thought i would ask, because the manual also mentioned the possibility to run it off vacuum but i guess that is still only for a boosted engine then

as for the lines, my plan was to add a new 3/8th fuel line, and plum the stock 1/4 as the return line