LS rockers on a Mopar?

I wonder if the LS rocker conversion was done in an attempt to correct an issue with those heads.On my Speedmasters, the stock rocker shafts don't fit the rocker stand saddles very well. It's a loose fit and they wobble. I don't know if this is a common issue with these heads or not. I'm not sure what the best (and most cost effective) solution would be . I haven't put much thought into it as I'm not in a big hurry to use the heads yet.