I have a Northtech Defense .223 Wylde barrel that will be arriving in a couple of days that will be pre-dimpled for a gas block.  I will be mating it with a Battle Arms Development Titanium .625 set screw style gas block.  

Will the dimples on the barrel automatically provide a gas port alignment feature when I go to install the gas block?  Or would it still be a good idea to purchase a gas block alignment tool like the one from Uniquetek? AR-15 GAS BLOCK ALIGNER

Also would blue Loctite be good enough on the gas block set screws or should I use Rocksett?

This is my 1st AR-15 build so forgive my noob questions.  I appreciate your help and input!

That question would be best answered by the manufacturer since they can vary but I will give it a shot. The dimples should be indexed in relation to the alignment pin on the end of the barrel so you should be good for " alignment". What is hard to know is what spacing of dimples they will use and does it mate up with the gas block setscrews for the particular gas block you are using. Some manufactures use a .400 spacing between the set screws and some use .450. Some only dimple for one hole ( the one closest to the shoulder/ seat for the gas block ) and some give you two but it may be of a different spacing of your gas block...

I use rockset for the set screws but loctite will get you by in a pinch.

Hope this helps and did not add to any confusion.

Never assume that the factory pre-dimple barrel will automatically line up your gas block with the gas port.  I've always measure the distance and size of the barrel's gas port and correlate that with my gas block/FSB.

Use rocksett at your own risk! I've only used blue loctite on a dozen of my AR's, and twice I've had to drill out the gas block because the set screws were stripped.

Proper dimples will be 180 degrees opposite the gas port, and aligned with it.

Proper gas blocks will have the rear setscrew hole in line with the gas port hole.

The two should always mate up correctly, if both parts are properly made.