[Sizzler]

The side-oiler might be better if the rumors of more extensive quality control checks at the factory are true. Better checking for thin points in cylinder walls, possibly.

Otherwise, as long as they're both seasoned blocks and not NOS ones that've been hanging off an engine stand for the last 30 years, they should be pretty equivalent today. All the crossbolting, and even the oiling pattern can be duplicated and bettered today given access to a good FE shop.