any benefit to swapping heads?

If the x heads have never been touched they don’t have hardened valve seats. I don’t think it is worth doing a simple head swap. You know the 360 heads are good and have hardened valve seats. The x’s are not worth the effort in their stock state and can be a reliabilty concern. That said the x’s are valuable. If stock appearance of the head means nothing to you there is no real reason to put money in a 50 year old casting. There are just to many better options, but there are people that want those heads to either restore a car or are required to run that head. If thats not you sell them and put the money towards
a better head. I’m VERY VERY happy with my x heads, but to get them to flow 278 cfm cost me $3000 in work. What will $3000 get you in a one of the newer castings.