**600hp sbm block limit? Or is it bs!!**

Those caps actually make the block weaker, as you found out. There just isn’t enough materiel there to support the added load the bolt puts on the pan rail and the main bearing bulkhead.
They are not a good idea. Especially on a 360. I could see using them on a T/A block but thats more expensive than an aftermarket block. Ultimately if you have the money run the aftermarket block but like a lot of guys I didn’t have the money at the time and I got to see the true potential and I don’t think I found the end at which a stock block fails.