Mike: It's not really a case of who's bow does what. I'm trying to suggest to you that what you think is happening is not. You cannot change the laws of physics. You might gain a little on the drop w/ those new 5" vanes w/ alum inserts, they will weigh around 360, as that's the same arrow in packages w/ Excals. Are you shooting to sight in from a bench rest or offhand? Here's yet another site w/ k.e. and ballistic calculator that may help you figure out what's going on. Frankly, I'm not smart enough to use this one for other than k.e. but the info is all there.
Here ya go, and let us know what you end up w/. http://home.att.net/%7Esajackson/ke.html