How do the idle mixture screws come out of the rear carb 1968 4431 number? Got the weird screws, will not come out..

And,

What location do the correct intake studs/ bolts go in ? Just ordered up the repo set and not sure what holes to use for the studs, nuts / long / short and the bolts..

Thanks,

There are tiny set screws that go in at an angle (Allen head) which are covered with a lead plugs from the factory. DO NOT force the mixture screws past them without removing them, the 68/9 mixture screws have a "waist" that is very thin and delicate, the screw will snap in half if you force it and correct reproductions of those screws are not available (incorrect brass reproduction screws shown in the first picture).

Thanks Scott,
Probably some emissions control attempt back then.

I believe it was so you could only back the mixture screws out so far and not get the idle mixture to rich. Ron