Yeah Brian..it's a 440. The pickup screws into the block....from the bottom, right where the oil pump is located. It was tight as a **** when I pulled it out. You thinking sucking air through the threads where it screws in??
THAT I CAN SEE, I would have inspected the threads real good, it could crack in the thread and be very hard to see and under a vacuum air will get through the smallest crack so, did you inspect the threads or just look at the pipe?
