Hydraulic Roller Lifters w/LA Block?

Our 71 casting 340 block was exactly the same way as yours, OP. The chamfers leading down into the lifter bores were very irregular; it is like the chamfer was put there at varying depths, and I surmised it is machined there to just provide some clearance at the top of the bore casting for the main lifter bore finishing tool.

For the MRL's and others, the info on the lifts of the cam that had not issues with the MRL's versus the lift that you have in this cam needs to be considered. And I thought the MRL were solid rollers, not hydraulics.....??? The Hughes lifters say they are OK with the varying chamfer heights. But I am sure the have a max lift; they give good dimensions.