[olddog]

The rib issue:

Well if you look at the ends of the block, the two banks are tied together well. So if there is going to be any flexing it will be at the midle two cylinders. If you pay attention, between each cylinder, the block is solid all the way out to the head bolt bosses (bosses may not be the correct term). These bosses are forming a small "I" beam. Considering it is billet. My gut tells me it is going to be quite strong.

Put the block in a press and measure the deflection. In an engine that will not generate 1000 lb-ft of torque, I would think 500 lb of force in the center of the block would be way more than anything the engine will do. The motor mounts alone will put half this force just holding the engine in place. Anyone expecting the block to flex from the engine's own weight? Measure the first block and put this one to bed.

I think too much emotion and not enough engineering calculations, but actual field tests will prove it one way or the other.