My lifter bores are worn & leaking profusely (oil psi gauge on oil sender boss is oscillating wildly from 20 to 5 psi) during breakin after about 5 minutes so I shut it down but until then it was ~40 & fairly steady. the bores were loose on assembly so I shoulda dealt with it then or found another block. Someone mentioned olds 425 lifters will work but are .921" so either the lifter bores would need to be bored or the lifters' OD reduced if that is even possible but it would be nice to resolve this (if possible) without a teardown. thank you for your time. PS I was thinking Ma had .001 OS lifters at one point in time.