You can use 312 pistons in a 292 so 3.830" should not be a problem. BTW: you cannot use 292 pistons with 312 crank & rods
I didn't see what 292 block you have but all blocks that were machined as 312's were also machined as 292's. In other words, they were the same casting. ECZ, EDB(Cleveland), B9AE and even some rare C2AE 312's built as over the counter replacements and marine engines.
Nobody thinks twice about boring a 312 block .030 or .040".
I've taken apart blocks that were as thin as .068" that were not cracked. One was raced extensively. It was a 1955 292 bored .125".
I wouldn't put one together like that but .090" wall is probably all you need for street use.
One major change in block castings is the design of the cylinder walls. Up to the B9AE blocks the cylinders are thickest at the top and get progressively thinner toward the bottom. C1AE and C2AE are thinnest half way down. I think this was easier to cast, not a reliability change.
My 2 cents worth: If you are building a high performance engine, sonic test by all means. If it is a 220hp street cruiser, punch it out and don't worry about it.
http://ford-y-block.com 20 miles east of San Diego, 20 miles north of Mexico
