First off, how much hp are you making right now? I think the stock one is good for about 350whp.

 

I thought the point of a larger intercooler was to prevent loss... I would love for somebody to explain for me how it could be responsible for an increase in HP.

 

Less loss means less pressure drop. What this means is the compressor is not working as hard (lower pressure ratio) to provide same boost pressure in the intake manifold.

In turn, the turbine doesn't have to work as hard to drive the compressor. This will be seen as less exhaust backpressure with all the obvious benefits associated with that.

That's what an upgraded intercooler SHOULD provide, but no vendor has ever provided any pressure drop data on their intercoolers, as far as I've seen... it wouldn't surprise me at all if some of these "upgrades" have more pressure drop than stock.