what do you guys think about these?

It is the resisitor that fools your MAF I believe. Never tamper with the factory MAF unless you REALLY know what you are doing and have discussed it with at least two other skilled mechanics.

BTW, it is expensive to get horsepower out of a mod motor. That is the bottom line and there aren't any $49 shortcuts so fugghet about it...
 
Also, look at this guy's feedback. His responses to negative feedback are not those of a responsible seller that wants to maintain a good reputation. He's just like, "Yeah, what ever, got your money. NEXT!"
I would stay away if I were you. Again, just my opinion.

Good luck