https://bobistheoilguy.com/forums/ubbthreads.php/topics/4223331/Re:_centrifuge#Post4223331
I'm running two bypass filters and a centrifuge. The feed line that supplies all 3 is an AN6 line (nominal 3/8" ID, actual ID is 5/16".
The AN6 line feeds directly into the centrifuge. Upstream (between the centrifuge and the oil galley tap supply) I have two fittings which are AN6 with 1/8 npt gauge ports-these ports feed the two bypasses. One of the bypasses returns thru the valve cover. The second one and the centrifuge return directly to the oil pan. All three have separate shut off valves in line.
I removed (actually purchased a second pan), drilled holes in the side of it (above the oil level and below the crankshaft baffle), welded fittings on, and then swapped out oil pans.
My engine is the 3800 GM V6 transverse mounted. None of my hoses go anywhere near any pulleys. The link above shows my oil pan and drain lines; here is a picture of the top side set up:
All of my hoses are blue Parker Push Lock, rated for 300 degrees F and 250 psi, available on eBay, except the top return line into the valve cover, which is really nonpressure and is clear tygothane C-210A. The picture above is a little out of date, I added another shut off for the filter on the left.