I'm not sure what caroline's truck is telling you. He quoted from the inliners link that says mount the carb with the primaries to the outside and then shows pictures with the primaries inside , next to the valve cover. That puts the carb linkage farther away from the firewall. The fuel inlet is as far away from the fuel pump as you could possibly get it. The idle mixture screws are buried down next the valve cover. The purpose of not putting the carb fore and aft is to balance the distance between each of the intake valves and the primary throttle bores. Placing the primaries inboard assures the worst possible variation in distances between primaries and intake valves. ???
Caroline is showing a 292 and you have a 235.
To answer your question about using the 8 bolts. You said," the 2 end holes on the headers have a couple of studs there" . I am not at all familiar with the 235, but the 250/292 comes with short locator pins/studs on each end of the head and also two long threaded studs on two of the inboard bolt holes. If the 235 has the same locator pins and you are using steel tube headers you will want to use a bolt or better, a threaded stud. The end exhausts will probably leak if you don't. The 250/292 uses two of these threaded studs and two long and four short "thingies". How about we call them clamps? Pictured below is one of the original threaded studs and one of the long clamps.
stud
On my 292 with Clifford intake and tube headers, I used eight of the threaded studs and six short clamps.
DrewP mentioned the difficulty of assembling everything on the side of the head. One advantage of using studs is that everything stays in place by themselves until you are ready to put the nuts on. In this picture of my 292 on the engine stand there is not one nut holding it on. Everything is just sitting there.
I used a cable for throttle linkage. A cable off a mid '70s V8 was long enough that it loops around over the valve cover and then to the carb.
Engine
Throttle cable

'67 GMC 3/4 292 4spd