A 1974 Duster - My 2nd one, 41 years later!
All things happen for a reason. Ya just have to deal with it.
Believe me, I have done a ton of reading trying to understand what went wrong. When running a solid roller cam and lifters in an LA block it is imperative that you either "tube" the block, or "Bush" the lifter bores, or run CompCams 828-16 lifters, or else all the oil will fall right back down on the crank through the series of 1/2" holes in the main oil galleys.