Xulfiqar bhai; first of all I am glad to hear from you some insights on topic of my interest, I am glad you gave a good insight, we keep on experimenting and reading material to get good performance gains by different methods we can find online or from masters like you...
One correction it wasn't 58bore, I mixed it with XL's .. the engine we bore has originally 69mm and was bored to 72mm, we do not have any dyno or high tech stuff and usually rely on track test to see if we got increase or if it failed. I will keep this flame propagation speed in mind next time for sure... but we had seen some really really like awesome results in few modification this is one of them, but yes our failure list is far longer.