Vacuum takeoff at carburetor

[Grant Bowker]

I'm sure there has been discussion of vacuum takeoff adapters that fit between carburetor and manifold in past but can't find it. If anyone else finds it, can they link the thread here (or move this post to go with the old one)?
Recently ebay yielded two different patterns of vacuum takeoff spacers. Both are sized for 1-9/16 throat, 3/8 mounting studs on 2-11/16 c-c. The thicker is just under 1/2 thick with the vacuum passage 5/16 at the outer end but only accepting a 1/4 drill at the inner end. It is possible it was originally 5/16 full length as there is some distortion in the plate at the inner end. The thinner version is just under 3/16 thick with the outlet as 1/8NPT. The open areas for vacuum flow are surprisingly similar give the difference in thickness. The thinner one might not need new studs while the thicker one probably would.