An engine builder would never compare different engines and applications. Think for a moment what affects bearing loads ? Here is a few things that come to mind.
1. Piston weight 2. Rod length and weight 3. Rpm obviously
The heavier the piston, rod and the longer the rod the more load you will see at the bearing. I shouldn't have to tell you this. Compare with other naturally "bullet proof" motors like the 2j and the 4g63 and you will see they take more abuse than others in a street application. Also i find it silly that you are comparing a race motor to what we use on the street. Just because you can make 1200 hp does not mean you should for a street application. It has to live for a few thousand miles on the street vs a few hundred at the track right ? Harry