Nope. If there was, Chrylser would have offered it over the counter like they did with the T/A block.
The T/A block is the weakest of the series of race blocks...T/A...X and then R blocks in that order.
I've honed probably...I can't even guess but hundreds of magnum bores and they hone no differently than any other production block. Even the T/A isn't much harder. The X block...you know you are working with a pretty good piece of cast iron. We will see if the R block I have is even harder than that when I get going on it.
