I have done a 3" stroke 6.22 rod in an 880 block still going strong after 9 years.
The blocks came in both 4 bolt and 2 bolt mains. Mercury marine used then for the 6.2 Lt marine engine and I have seen them in both 2 and 4 bolt versions and they have no issues. They are a very heavily loaded engine in a larger boat they get used in and run at 3800-4200 all day long under load with cast pistons and PM rods.
Using steel caps makes the block stiffer and allows more power to be put to the crank without the caps flexing. Makes a tidy street engine or moderate race engine package.