If you are serious you will need to find an unmolested C6AE-H aluminum police interceptor manifold.
Also keep in mind that of all those Holley carbs listed you will want one that meets the specs for the C9AZ-U, C9AF-U, C5AF-BV carbs as it is the largest. NHRA doesn't care about having the exact OEM carb anymore, you just have to have one that has the proper throttle bore and venturi diameters. Those three carbs have the size spec'ed as 1686x1686/1375x1437 which translates to primary and secondary throttle bores of 1.686" (i.e. 1-11/16"), a primary venturi of 1.375" (1-3/8") and secondary venturi of 1.437" (1-7/16"). Those are the sizes used on all Holley 735/750/780 CFM carbs. Don't waste your time and money trying to find a 48 year old OEM carb Just get a Quickfuel SSR-780-VS and block off the secondary idle adjustment per
http://www.nhra.com/userfiles/file/N...edProducts.pdf.
Life will be much easier.