108octane and 93 octane

[93stang burden]

ok i have had some bad spark knock with my new 331. so today i ahve added 5 gal of 93 and 3 1/2 (@8.50 a gallon) of 108. tomarrow i plan on driving to work. has anybody ahd any experince mixing ??

should this be about a 100 octane??

any advice thanks
henry

 

[notchback]

you can do the math... but why not knock down timing... since it's free ??????

im just saying

 

[93stang burden]

i' have played the timing game. been all the way down to 6* and nothing.