Mad Dart
Im the shop making the main caps you mentioned. I have a few sets out there running. One is a member on here with a 650HP+ SBM, runs strong all the way to 7500rpm.
Ways to make the SBM survive
Good balance
Light rotating assembly w/quality parts
ARP Studs NO 4 BOLT IN A FACTORY BLOCK
Good main caps
Hard Block Filler
Croy treatment(it does help)
Tune it to run right Detonation is a Block Killer
And pick the right block for the job SONIC TEST
Yess 500hp is a stretch for a factory build engine with cheap rod bolts, heavy cast pistons, heavy low quality unbalanced rods/crank, Low quality valves ect.
The factory stuff is fine, to a point. Mopar(and all the rest) dont put the BEST parts into millions of engines, they just can not afford to. So they use the cheapest stuff that will work for a good long time under "normal" driving conditions. I think this is where all the stories come from is guys using factory stuff to make a full on race engine with no upgrades to them.
You work on a factory rod and yes they can handle a lot of power, but it takes a LOT OF WORK TIME AND MONEY.