Woody, Don't know the exact spec. However, when I redid mine awhile back, I took them to my friend who's been doing these motors for years. He actually Hammers them in. The rationale is the abrupt shock is less stress overall in the fitting process. I tried .002 over guides and they wouldn't go. We turned them to about +.0005 and heated the jug with a Bernz o matic torch 'till it was warm, pulled the guides out of the snowbank and bam, bam, bam they were in! I've always chided him on his crude method, but in the right hands, a hammer can be a tool of finesse.
Long and short, the holes in the block don't change much, and std or slightly oversize should do the job.
This may not help you, but I thought I'd pass it on anyway.