Can any one tell me what the difference in these two are and which one is actually better? Any help or comments will help. Thanks

i know SLP makes a good product, but i hear alot of good things about Granatelli too. either would be a good choice IMO

Man I missed this one. If you have an LS1 (I assume because of your S?N) the stocker is good for almost 400 rwhp. Going to a bigger MAF will not get you much of a gain unless you have some serious other mods. FWIW, I have both a Granitelli and a SLP Z06 MAF. The SLP unit makes my car run lean so if you wanted to run that one you need a tune. I run the Granitelli on my car now and it has been fine but I don't think it's any better than a stocker. I got both of these units for free to test and play with, I woud not have spent money on them at this point.