I've had iron and aluminum in street cars and would NEVER consider an iron block again......especially the iron blocks available for big blocks and HEMIs.

The stock 440 block in my 499ci Indy 440-1 engine weighed about 240#. An iron aftermarket block is well over 300# and they aren't exactly state of the art.

My 526ci HEMI uses a KB water block without issue and it came in a about 140# w/caps. It is a far better choice than the currently available iron blocks and is repairable in most instances should the unforeseen occur.

With current piston and ring technology, along with vac pumps, the sealing issues are not what they were years ago. As long as no high-end manufacturer of iron, or CG blocks is willing to take the plunge into the MOPAR market and release a cutting edge piece that doesn't weigh slightly less than the anchor on the Titanic, aluminum is the way to go and well worth the money.