My girlfriend's AR has a iron sight gas block and I'm am wondering what I need to do to change that. So I can put a quad rail of some sort on it. Any info would be awesome. I want to pick everyone's brain. Thanks.
Unless I am misunderstanding getting a Sight-tower type gas blockoff is generally a bear. There are 2 taper pins that need to be drivin out and I know with my Stags I bent several punches before I took it to GDS Enterprise and paid them $20 bucks to driveout the taper pins. Best $20 bucks I spent. GDS is in South Austin on Ben white about a mile from I35
Also you need to decide if you want free float hand guard and if you want the gas block to be low profile and go under the forearm.
They are kind of a pain. You could also try completely destroying the front sight to where it is no longer useable again by taking a grinder with a cut off wheel along the running end of the sight right through the pins and splitting it open
I took my factory block off and replaced it with a low-profile block from Troy that I bought on Amazon so I could install the Troy free float hand guard. Like they said, you just need to punch out the pin.
Free float hand guard can significantly improve your accuracy. As sated earlier, after you get it off you can replace it with one that would fit under the hand guard if you wanted to or one in front of the hand guard with a sight on it. Clamp-on (with set screws) gas blocks (with or without a sight) are available and easier to deal with than driving pins out. Check out Brownell's for a large variety of gas blocks.