You have me curious now. I am going to have to drag out my spare 59 block (no line behind the side cover) when the weather breaks here. I always assumed that the 59-63 blocks (those that did not have the line, now that it appears that some do have the line) Could not use the milk bottle lifters (regardless of the material they were made of, i.e. pre 1990 manufacture for steel cams, post 1990 manufacture for steel or cast) simply because the solid sides would prevent any or most of the oil from traversing through the lifter oil galley to the internal drilled oil passage for the rockers. Further, I also assumed that the reason I have never seen a milk bottle lifter in a later block was just for that problem, and that the at874 lifter was used because that lifter was not solid sided and would allow oil pressure to pass the lifters to get t the rockers. To be truthful, it was Charlie Baker, Pat Smith and Tom Langdon who provided me with that info many years ago now and I was never willing to risk a cam or rocker failure, particularly a rocker failure given how darn expensive they can be to have rebuilt.
Last edited by Dragsix; 01/25/2018 4:50 PM.
