First of all, I don't recommend doing those speeds on public roads, the best way to see if mods have improved power is with a dyno. That said, the first things I would check is your steering head bearings, tire pressure, wear, and balance (all already mentioned).
More than likely, it is your steering head bearings that need to be tightened. If it isn't, I would look at your steering damper (depending on the year of your bike, you should have one stock) or possibly the suspension. If the bike is unloading the front too much under acceleration it can become unstable or if you have lowered the front too much it can get twitchy.
Rarely is the question stupid, but sometimes the answer is
you need to run everything you read online through your own personal BS meter to determine if it makes sense to you.