Yellow Rose has many times pointed out the oil timing differences
On the forum. It is different. The Chevy is right in the center of the saddle, the sbm is slightly to the side. In my latest build I had my bearings slotted on an edm machine. When you look at the orientation of the bearing to the block feed, you can only slot in one direction. However imho the slot not only increases the dwell time, it shifts the oil timing as well so that the oil passage in the crank can access full flow from the block when the crank oil hole is in the center compared to from stock, only slightly to the side. Just like the Chevy. Guitar Jones slotted bearings and so does Sanborn.
Hemi engine bearings from Mopar performance also came slotted.