normal 528 and 540 ci combos require on an aftermarket block, because they require a 4.500" bore to arrive at that ci.

528ci is 4.5x4.150, 540ci is 4.5x4.25.

A 4.150 or 4.250 stroke should not be a problem, but the 4.500 bore is pretty impractical for a stock block and is not going to happen.

4.375 bore is a more reasonable expectation for an OE stock block which will give 499ci with the 4.150 stroke or 511ci with the 4.250. Both combinations as well as slightly smaller 4.350 bore variants have been done to death just because they work/because a guy can't go much bigger on the bore without going to an aftermarket block.

I thought you had built a 493/499 sometime in the past but maybe my memory is shot on that