He is full of crap on a lot of issues.
First, we need to delineate what "strength" we're talking about. There is a big difference between how strong the main webbing is and how much power it can handle without deforming/exploding.
Many of the 2-bolt blocks had additional webbing, which means the webbing is stronger, but there are only two bolts holding the main caps in place. Depending on the casting, the general (very general) accepted guideline is that in order of weakest to strongest it goes A) 2-bolt, B) 4-bolt, C) a 2-bolt block machined for 4-bolt.