does anyone know if you can slightly modify or what you might have to do in order to fit an aftermarket intake from a 3.5 on to a 3.7 h3 motor?

Drew

 

It is not the motor size itself, there are two differences between the 3.5L (2006) and 3.7L (2007). The MAF sensoris different and they are not interchangable, a 2007 MAF will not fit the hole and make a seal in a 2006. There is also an emissions breather on the front of the air filter box on the 2007 that is not present on the 2006, so you have to deal with that open hose with a small filter or the like to prevent crud and water from being sucked in it.

So it is more than a slight modification, it would be an irreversible bastardization of sorts. Good luck.