I'm confused. My FSM calls out a Carter MS-4434S fuel pump for 440 H.P. It says the 4589 is for 383/440. I ordered a Carter 4434, and am installing it now, and it has a 3/8" inlet, but the threaded outlet is smaller than the 5/16" line to the vapor separator that I have. Is this wrong, or is there supposed to be an adapter?