What kind of lifters? I just installed Lunati (Morel) hydraulic lifters on mine and now I have low oil pressure. The oil band on those are twice as wide as the flat tappets and Im getting leaking out of the bottom. Comp rollers has the more narrow band and that should help it. I just dont want to tear it all back down again now,that will be a winter project. I think Howards also have the wider band. At idle the pressure is 15 lbs so I just keep the rpms up a little. Driving its fine 40- 45 lbs