installed a used wrecked 04 z570 engine in a 04 z370 chassis.bled out oil pump using bleed screw,lots of oil. started engine with line from oil pump to fuel pump off. held up on lever and watched oil exit pump, just oozed out of pump slow,very little oil and no pressure. repeated procedure a number of times,no luck.by the way i used premix to be safe.removed pump disassembled drive is working and didn't find anything noticable. i have another pump off the 370 which has 2 lines going to intake. if i plug one line and only use 1 to fuel pump will it be the same or change inlet from pump that came on engine ? how long does it usually take to bleed out ?