You dont need both ...one or the other.... and both work great , most people will tell you studs are better, but pulling the head is a pain in the ass after that, i used to have studs and changed to bolts.....they work perfect.
Yea studs are no problem at all to use with the hex in the top. I have had my head of twice since the install of the hex-design studs and no problems what so ever. The just spin right out with no resistance what so ever.
I think its much easier to manufacture a stud than it is a bolt/socket head cap screw, I have heard they (studs) are much stronger, but who knows for sure!!!!
I ordered mine more than a year ago and never specified and they came with them (the hex), Got em from Titan Motorsports, spoke to Jack, they cut me a deal cause I got a MHG and Studs and an SAFC at the same time.
the studs dont use a "hex" to install, they use an Allen key. the studs dont use a 6-point socket to install into the head. technically, you should just chase the thread in the block and then install the studs "finger tight". they are Never supposed to be tightened into the block. if you are doing this in the car, put the Washers in the head FIRST, then lay the head on top of the block and then drop the studs into the head and use either an Allen key bit for your socket set or a T-handle Allen key; those are the easiest. just run them down but dont tighten them into the block. if you put the studs in and then try to put the washers over the studs, they wont clear the head casting.
^^^All that is correct ^^^ Sorry if I was ambigious.
If you want to get specific, I have a SERIOUS amount of tools and only 1 socket I have fits on the nuts for the studs and fits past the casting in the head. Make sure you have a 12 point 9/16 deep 3/8" drive socket. My 12 point deep 1/2 drive interferes with the head.