Ok so the B20 redlines at 6300 rpm. Now I have heard that all you need to do is toss in a forged crank/pistons/rods and you can redline it to 9k rpm safely. But, someone told me at the performance shop that the block will fail at 9k rpm even with the above internals.

Is this BS?

 

It is and it isn't. The block is not the problem it is the stroke of the crank. More importantly the piston speeds with that certain stroke.The crank does not need to be forged and the rods/pistons will not fail from this. You have to worry about piston ring failure, rod berring failure, main cap failure, and crank seal failure. But when all is said and done you replace the rod/main berrings, added to a good set of rings and a properly tuned and ran setup it will last a good bit. Now I am not saying 200k oem honda reliability but it will last a good bit like I said.