New Castrol oil for the classics! "Castrol GTX Classic" 20W-50

I'm super excited to try this in my air-cooled Honda motorcycle. It's a blast to shift it at high rpms. The higher anti-wear additives in this oil are definitely needed in my application.
Sadly, it will not work on my 1998 Ninja 250 due shifting problem. The one that works on mine is 10W-40 synthetic oil formulated for motorcycle
Glenolden Pa.
I haven't seen the Castrol high zinc "Classic" yet in my local Walmart's but, with my stash of Valvoline VR1-Racing Racing 20/50 (for my older Corvette) becoming extinct I hope to find this Castrol high zinc offering soon! (the price of VR1-Racing 20/50 is off the charts expensive!)