go to the hardware store, buy a gallon of pure tolulene, mix it with your high test 89. i will find a conversion chart for octane booster,and post a link. i have done this repeatedly on a high comp 318 ,and it stopped the ping . i opened it up years after rebuild and its got clean combustion chambers too.
i think its $3.89 a gal at do it best
man i cant believe im actually recommeding this! so im not,iam just throwing a new idea out there for those who think outside the box. alos i think its the same ting as some offshelf octane boosters. i swear!
Save money...if anyone has actually used this and had a bad expirience they probably mixed wrong.
no tolulene leaves no residue,burns relatively clean shouldNT affect emissions,terribly cancerous
(i dont use in my hotrod)