Well, finally got all the holes completed for the lifter bore oiling holse in "INDY1". Fortunately, a previous owner had done the really hard part by drilling the holes on top the oil gallery so a longer .125 bit could be used to go through the other side of the oil gallery down into the lifter bores. I drilled those and gave the lifter bores a quick hone.
They also drilled valley drain holes down into the block for each pair of lifters.
This picture better shows what I'm trying to describe.
http://community.webshots.com/photo/80287028/86896713kVbzxS
Now, the other block "INDY2" doesn't have any of the lifter bore oiling holes drilled or the valley drain holes bored. Not sure what they made those drain holes with. Maybe a machine shop, or if drilled, it had to be a very long bit to reach down in there, without the drill chuck hitting anything.
On INDY1, my .125 bit is a long 6" bit, permitting me to complete the process where the access holes were.
On INDY2, my #21 bit (for the access holes so that I can use the 10-32 plugs I have) isn't long enough (and can't find a long #21 bit) to do half of the holes without the chuck coming in contact with parts of the front, rear, and valley braces.
Now, here's my point. If I move the holes at the ends of the block enough so the drill chuck doesn't hit anything, the final oiling holes down into the lifter bores would be offset from bore center by about half the radius of the bore. So the oiling hole into the bore would be somewhat eliptical because of this offset.
Would that eliptical shape make the hole affectively too large????????????
Here's a picture of INDY2 with no valley machining done. There's drill chuck interference that occurs with one lifter one each end of the block and one at each of those four vertical block stiffeners (particularly the top where it's fat).
http://community.webshots.com/photo/80287028/80288772rGHkve
They also drilled valley drain holes down into the block for each pair of lifters.
This picture better shows what I'm trying to describe.
http://community.webshots.com/photo/80287028/86896713kVbzxS
Now, the other block "INDY2" doesn't have any of the lifter bore oiling holes drilled or the valley drain holes bored. Not sure what they made those drain holes with. Maybe a machine shop, or if drilled, it had to be a very long bit to reach down in there, without the drill chuck hitting anything.
On INDY1, my .125 bit is a long 6" bit, permitting me to complete the process where the access holes were.
On INDY2, my #21 bit (for the access holes so that I can use the 10-32 plugs I have) isn't long enough (and can't find a long #21 bit) to do half of the holes without the chuck coming in contact with parts of the front, rear, and valley braces.
Now, here's my point. If I move the holes at the ends of the block enough so the drill chuck doesn't hit anything, the final oiling holes down into the lifter bores would be offset from bore center by about half the radius of the bore. So the oiling hole into the bore would be somewhat eliptical because of this offset.
Would that eliptical shape make the hole affectively too large????????????
Here's a picture of INDY2 with no valley machining done. There's drill chuck interference that occurs with one lifter one each end of the block and one at each of those four vertical block stiffeners (particularly the top where it's fat).
http://community.webshots.com/photo/80287028/80288772rGHkve
) you could step the through-hole size down from .125" to, say, .100" or thereabouts. You are certainly getting to do some unique work on those...good luck! 
