hey bill, you can order octane booster from jegs or summit in a few brands. the stuff does work as for the amount it will rise the octane?? the bottle will tell you how much to add to a tank of gas.. i have some what tested it on the dyno to see how well it works and was surprised how well it did. ran 1 bottle of the nos brand to ten gallons of 91unleaded. the engine was a 13to1 bigblock and did very well and made within 10hp of cheaper race fuels... i'm not saying it will be safe to run in every 13to1 engine but i would feel very safe to 12to1 with the stuff. good luck