Perzactly!
Siamese cylinders will generally be more stable, because of the additional metal at the bottom of each cylinder. In some cases, siamese cylinders can have different cooling requirements, but that's certainly not a deal-breaker.
There are different methods of filling water jackets in a block, to provide more stability. Anyone remember using cement and rattling the outside of the block with a muffler gun to help the stuff settle? A few years back, we even had an epoxy-based resin filler we used. It was nice, because it had the consistency of room temperature pancake syrup, so it would pour easily and settle uniformly.