Block out of square

In all the years I've been in and around machine shops, I can say that that is one surface that was NEVER checked on any build.

You'd have to REALLY try and screw up a line bore or hone to get that result. Just a guess here... your line hone set up would have to be in the .090-.100 off to obtain that result. No way would the bores be close to completely uniform in finish if the bar was that far off.