Hello, looking for an under carb vacuum port for 3 bolt(97) carb. The thin kind, (not aluminum 1in) as used for heater or Columbia rearend. Yes, I’ve googled the shit out of it and cannot find one. Any help greatly appreciated! Thanks.
You may try "Speedway Motors" they should have an online catalog. There is another option. Phenolic sheet is pretty cheap and your very best racers use spacers made from it. Now the upside is that it is really easy to work with and you can cut and shape it with wood working tools. If you are going to install a vacuum port you will want to use 3/8-1/2". 1/2" will be better.
What exactly do you need? If you look at the cross section above, you will see little capped holes that can easily take a pressed-in brass tube or be drilled and tapped for a ported access. Then look at the front view of the throttle body... between the idle mix screws there is a bump obviously made as a location for a manifold vac port. Brill it in a little ways, then drill a smaller diagonal hole into each barrel.
There is this 3/4 aluminum one with vacuum ports on ebay 253828829755 This guy has a half inch thick with no ports that could probably be drilled or you could make your own. 232198033849
Thanks Bruce, I considered that, but I’ve seen the plate in the pics above before, and thought that was a better way to get manifold vacuum for tri power on an sbc, without drilling a hole in the manifold. I could be wrong though, I’m definitely not an expert!
Muttley, Cool piece. Are they still being made? If not how hard are they to find? Will it work with a Holley 94?
Mr48chev, is doing you a solid. This is just what you need, it is an aluminum spacer already drilled and tapped for your vacuum port. It is tapped for a 1/8 pipe thread.[/QUOTE] Thanks, but I have seen these, and just too tall to put on 1 carb in a 3-2 setup.
Why not hollow out a carb stud and pull vacuum through it? Pontiac used them. The manifold was drilled all the way in. 1965-hollow-carb-stud
Sure, that’s only $84 for three spacers, but hey, he can hook up the vacuum! I like the drilled stud, it’s the cleanest and cheapest solution. If you know a guy with a lathe make one.
I’ll take cheap and home made over 800-chk-book every time. For me personal satisfaction enters into it but YMMV.
No my mileage doesn't vary one damn little bit more than yours does. I fab most of my parts when ever I can. But if you take those adapters as an example figuring time and parts I would just bet there is no way in hell ,to make the things for much less than the $28 asking price. Some times you have to be smarter than what you are working with----but YMMV.
Nothing was said about making the risers, my comment was in favor of the drilled stud. It does the job the cheapest and doesn’t change the appearance of the manifold and carburetors. That would be smarter.
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