When I used to drag race in the early 80s, we ran Moroso Octane booster - came in a 1 gallon can - was supposed to work well and it did stop the pinging on my 11:1 engine - 240lbs cranking pressure on compression tests. Not sure if they sell it anymore or what it actually did in terms of raising the octane rating though. As I remember, I added a quart to 15 gallons plus or minus.