basically, yes, however, my personal cutoff for 93 is 160. But, if you have your timing advanced, then you'll need to come down some more. So, for 155 lbs. with +5 timing, I'd use a higher octane or a mixture there as well. For 160 to 170 I'd use 100 octane. 170 to 180, 100 - 105 octane will probably be alright, but 180 and up, I'd say 110 all the way.
Honestly, I believe if your gonna go with race fuel, you might as well get some 104 at the least. I run a Sunoco 104 with oxygen. They say the oxygen is good for another 3% on power, but you might have to jet up a tad for it. But, Oxygenated fuel is like crack, once you use it, you'll never go back. My compression is 150 with +4, but I'll be moving it to +6 and my compression should be around 160 after the rebuild. The oxygen is so worth the cost, if your gonna pay for the octane, you might as well get some added go go juice out of it.