This has always been confusing. I have a 6 qt "Hemi" pan bought from Chrysler on my B block. I use the windage tray and also utilise the straight 3/8NPT pickup. Measured all of this using straight edges and the pickup sits about 1/8" off the bottom of the pan. So I assume it is ok. My son's 73 400HP Charger came with a factory windage tray and the 2-3 bend pickup which we reused when we repowered it with the 440. Both seem to work.