At 28" the spine will be pretty marginal with a 100 grain tip. You can try it and it might work. You could also try a heavier, longer vane. I assume you're shooting Blazers. Seems everybody is jumping on that bandwagon these days. A heavier vane would also stiffen up the dynamic spine a bit.

There is another option. Check at Lancaster Archery Supply for weight tubes. I believe they are made by Carbon Express. There are different size ones.

Of course there's another option. LIMB BOLTS. Nothing says the bow has to be maxed out. Just knock it back to 65# and shoot away. You'll probably find a bit better accuracy, too.