I’ve been very impressed with my EK ZZZ. No apparent stretch with 75 passes on it. The research I did before I bought showed the ZZZ to be one of the most popular chains among the high hp busas. I did hear a couple of isolated complaints, however. I’m not sure if it was a bad batch or what. Overall, it seems to be the most common choice of the Street Turbo guys. As for as I know it has the highest tensile rating of any 530 sealed chain on the market. The ZVX is a great street chain for stock near stock bikes that might see limited strip use. Both are “X-ring†type chains, the ZZZ has been slightly lightened. If you drag race only, the DRZ2 is a good choice for a non-sealed chain. I don’t usually recommend a non-sealed chain for street use.
PBI is a good sprocket company. They have been around for many years. I used to sell them as a top of the line sprocket 17 years ago when I had a shop.