I think this really depends on the rider and how much time they have spent on the "race bike" setting it up and getting used to the differences. On some tracks I was able to go much faster with my built race bike, but on others I actually went faster on a closer to stock bike because there were less adjustments and less stuff to worry about. I did a 1:23 on a stock bike at the Streets of Willow and I did a 1:32.8 at Mid Ohio on my race bike. I have raced both configurations at Shannonville, all on a stock 600CBR but I can't seem to find my times anywhere from those races and I've never ridden the new track at Calabogie.
However, I think that if you are running that close to lap record times on your stock bike then you are doing pretty well. I've always been of the mind set that it is better to ride your stock bike as fast as it will go, before moving up to a fully race prepped bike. Just gets you more comfortable with the feel of the bike and understanding what it can do before throwing in all sorts of variables like gearing, motorwork, race gas, suspension adjustments etc etc. Seems like you are doing well at what you are doing and when you are ready to start adding race components to your bike I'm sure you will see your time dropping.
I hope that helps, it is a tough question
Misti