Originally Posted by svo347
Dead on Russ!!...
Ditto. Sonic checking is the only way to know for sure. Core shift and intentionally thin-wall castings leave a lot to be desired. Remembering that Ford only needed to ensure that they could be bored to 4.003" will help us keep in mind that engineers design to the minimum requirement. I believe that Ford once stocked .010+ cast pistons as replacements. While they may have also had others, you can bet that they were considered to be for racer's and not rebuilder's uses.
The XE blocks are not an exception. They have much beefier main webbing (not contoured like the production car blocks), but they are thin, too. The best case is to sleeve any block planned for a larger bore. However, by the time you sleeve 8 holes, you've got as much money into it as it costs to buy a new Dart or SVO block. I've been saying for years, what we need is a new Cleveland block!