Super 6....can't put it off any longer. manifold questions

Ok my Slant brothers, please help walk me through the Super Six conversion. of course I am running the dart 66 with 225 with the original holley and rod type pedal. I have the article and read it 20 times. I have the materials list and I am ready. I also have the owners manual, and manuals for the Carter BBS.
I have found almost all the required parts. (just missing the throttle return spring, easy enough to fake I suppose with some angle iron)
My first concern, removing the manifold.
THe manifolds were removed when I had the engine rebuilt last year. He busted 1 stud so that one is now bolted on.
The rest of the studs dont have much thread showing, meaning I wont have much room for a thick gasket. I have 2 gaskets ready to go depending on what works best. I have the crushable thick Remflex. I also have the thin Felpro.
First question: if I am able to remove all nuts without busting a stud, why would I then remove the studs and upgrade them? Wouldn't I run a great risk of busting a stud in that process? The only reason I can see for removing the studs is so I could get longer ones so i can use the Remflex gasket. Please give any advice for the removal process. I have never done this before. Thanks in advance. You can see in pic the stud way at the front has no thread sticking out of the nut. And the manifold I am installing seems to have longer ends than the middle section. like maybe longer by 1/32 of an inch. if that makes any sense

throttle return cu.jpg