Not enough octane? what you guys think?

I agree. No 10.5:1 iron headed engine can run on 89 unless you have severely retarded timing. Do a comp test and get some PSI #'s. That will give you a better idea of your static compression. I bet if you installed an MSD dist, with the 18* bushing, 2 light blue springs, and set your initial at about 16*, and add 91, your gonna run alot harder than you do now.

No it will not feel like nitrous....lol.