Top oilers/center oilers have grooves in the block behind the cam bearings. Side oilers don't. So, if you use an F24 bearing in a 352/390/428/427CO block, you'll just have two entry points of oil to the camshaft through the bearing.
If you use an F33 bearing in a side oiler, you will need to oil through the pushrods, because the secondary holes in bearings 2 & 4 which oil the heads will not be there.