Not for nuttin, but I've never had an M55 "fail" at the housing. That includes streeters, stockers, lower-level circle track engines and reasonable drag cars.
The "Select" pumps ARE stronger, it's true. Whether or not they're "worth it" can only be determined by the buyer.
The ONLY small blocks we use a HV pump in have 2.650" main journals (400). Even then, for circle track, we stick to the standard pump. Continuous high RPM operation WILL suck the pan "dry" and starve it for oil. Higher capacity pans help some.
be sure to install the "sleeved" drive shaft (Melling IS-55E).