Not sure about the not for street, the regular VR1 is everywhere. I think the only major difference is the not for street has very little detergent the zinc is about the same
Looks like this, the zinc content for VV851 was supposedly higher then most, this is the reason it says not street legal, so people will catalytic converters on their daily drivers will not use it.
that's the oil I run in my race engine, only 10/30 synthetic got it through my napa dealer. always special order and cases only. I haven't raced in a few years so I don't know if its available anymore. I have 3 qts on the shelf. really great oil.
I found it on amazon
[ame="http://www.amazon.com/Valvoline-VV211-6PK-20W-50-Racing-Motor/dp/B00DJ4FIPQ/ref=sr_1_1?ie=UTF8&qid=1399865102&sr=8-1&keywords=vr1+20w50#productDetails"]Amazon.com: Valvoline (VV211-6PK) VR1 SAE 20W-50 Racing Motor Oil - 1 Quart Bottle, (Case of 6): Automotive[/ame]